Maxim Integrated / LP_Receiver_Wakeup

This is a low power example of the MAX1473 RF Receiver using the MAX32630FTHR.

Dependencies:   MAX30208 mbed-dev max32630fthr USBDevice

main.cpp@4:7320d2a40b92, 2020-09-04 (annotated)

Committer:
tlyp
Date:
Fri Sep 04 20:45:01 2020 +0000
Revision:
4:7320d2a40b92
Parent:
3:4af4942a59f2 
Added Comments for clearer execution

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tlyp 2:e4fcc385e824 1 /*******************************************************************************
tlyp 2:e4fcc385e824 2 * Copyright (C) Maxim Integrated Products, Inc., All Rights Reserved.
tlyp 2:e4fcc385e824 3 *
tlyp 2:e4fcc385e824 4 * Permission is hereby granted, free of charge, to any person obtaining a
tlyp 2:e4fcc385e824 5 * copy of this software and associated documentation files (the "Software"),
tlyp 2:e4fcc385e824 6 * to deal in the Software without restriction, including without limitation
tlyp 2:e4fcc385e824 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
tlyp 2:e4fcc385e824 8 * and/or sell copies of the Software, and to permit persons to whom the
tlyp 2:e4fcc385e824 9 * Software is furnished to do so, subject to the following conditions:
tlyp 2:e4fcc385e824 10 *
tlyp 2:e4fcc385e824 11 * The above copyright notice and this permission notice shall be included
tlyp 2:e4fcc385e824 12 * in all copies or substantial portions of the Software.
tlyp 2:e4fcc385e824 13 *
tlyp 2:e4fcc385e824 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
tlyp 2:e4fcc385e824 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
tlyp 2:e4fcc385e824 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
tlyp 2:e4fcc385e824 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
tlyp 2:e4fcc385e824 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
tlyp 2:e4fcc385e824 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
tlyp 2:e4fcc385e824 20 * OTHER DEALINGS IN THE SOFTWARE.
tlyp 2:e4fcc385e824 21 *
tlyp 2:e4fcc385e824 22 * Except as contained in this notice, the name of Maxim Integrated
tlyp 2:e4fcc385e824 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
tlyp 2:e4fcc385e824 24 * Products, Inc. Branding Policy.
tlyp 2:e4fcc385e824 25 *
tlyp 2:e4fcc385e824 26 * The mere transfer of this software does not imply any licenses
tlyp 2:e4fcc385e824 27 * of trade secrets, proprietary technology, copyrights, patents,
tlyp 2:e4fcc385e824 28 * trademarks, maskwork rights, or any other form of intellectual
tlyp 2:e4fcc385e824 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
tlyp 2:e4fcc385e824 30 * ownership rights.
tlyp 2:e4fcc385e824 31 *******************************************************************************
tlyp 2:e4fcc385e824 32 This is code for the MAX1473 RF Receiver circuit. This program will capture,
tlyp 2:e4fcc385e824 33 translate, and unencrypt messages received using the ForwardErrCorr.h format.
tlyp 2:e4fcc385e824 34 The example uses MAX30208 temperature data as an example. The MAX1473 will turn
tlyp 2:e4fcc385e824 35 on for 5ms every 500ms to check for data. If there is data to be read, the reciever
tlyp 2:e4fcc385e824 36 will remain on to listen for a full packet. If there is no data, it will return to
tlyp 2:e4fcc385e824 37 sleep mode for another 500ms.
tlyp 2:e4fcc385e824 38
tlyp 2:e4fcc385e824 39 Hardware Setup and connections:
tlyp 2:e4fcc385e824 40
tlyp 2:e4fcc385e824 41 MAX32630FTHR-> MAX1473 Ev-Kit
tlyp 2:e4fcc385e824 42
tlyp 2:e4fcc385e824 43 3.3V -> VDD
tlyp 2:e4fcc385e824 44 GND -> GND
tlyp 2:e4fcc385e824 45 P3_0 -> DATA_OUT
tlyp 2:e4fcc385e824 46 P5_6 -> DATA_OUT
tlyp 2:e4fcc385e824 47 P5_1 -> ENABLE
tlyp 2:e4fcc385e824 48 1.8V -> 200KOhm -> TP2
tlyp 2:e4fcc385e824 49
tlyp 2:e4fcc385e824 50 *******************************************************************************
tlyp 2:e4fcc385e824 51 */
tlyp 2:e4fcc385e824 52
MI 0:41ed595f83f5 53 #include "mbed.h"
MI 0:41ed595f83f5 54 #include "max32630fthr.h"
MI 0:41ed595f83f5 55 #include "mxc_config.h"
MI 0:41ed595f83f5 56 #include "lp.h"
MI 0:41ed595f83f5 57 #include "gpio.h"
MI 1:8834bc22c2e7 58 #include "rtc.h"
MI 1:8834bc22c2e7 59 #include "MAX14690.h"
tlyp 2:e4fcc385e824 60 #include "USBSerial.h"
tlyp 2:e4fcc385e824 61 #include "MAX30208.h"
tlyp 2:e4fcc385e824 62 #include "ForwardErrCorr.h"
tlyp 2:e4fcc385e824 63
tlyp 2:e4fcc385e824 64 MAX32630FTHR pegasus(MAX32630FTHR::VIO_3V3);
tlyp 2:e4fcc385e824 65
tlyp 2:e4fcc385e824 66 I2C i2c(P3_4, P3_5); //sda,scl
tlyp 2:e4fcc385e824 67
tlyp 2:e4fcc385e824 68 RawSerial uart(P3_1,P3_0); //tx,rx
tlyp 2:e4fcc385e824 69 MAX30208 TempSensor(i2c, 0x50); //Constructor, takes 7-bit slave adrs
tlyp 2:e4fcc385e824 70
tlyp 2:e4fcc385e824 71 char TransTable[] = {0x1F,0x18,0x06,0x01}; //Used to translate data for FEC -- Make sure it is identical to transmitter
tlyp 2:e4fcc385e824 72 #define SymmetricKey "RfIsCoOl" //Set Symmetric Key here -- Make sure it is identical to transmitter
tlyp 2:e4fcc385e824 73 Translator transRx(SymmetricKey, TransTable);
tlyp 2:e4fcc385e824 74
tlyp 2:e4fcc385e824 75 USBSerial microUSB; //Micro USB Connection for printing to Serial Monitor
MI 0:41ed595f83f5 76
MI 0:41ed595f83f5 77 DigitalOut rLED(LED1);
MI 0:41ed595f83f5 78 DigitalOut gLED(LED2);
MI 0:41ed595f83f5 79 DigitalOut bLED(LED3);
MI 0:41ed595f83f5 80
tlyp 2:e4fcc385e824 81 InterruptIn CheckData(P5_6); //Interrupt pin for detecting incoming messages
tlyp 2:e4fcc385e824 82
tlyp 4:7320d2a40b92 83 DigitalIn sw2(SW1); //Used on start-up to stay in active mode for re-programming
tlyp 2:e4fcc385e824 84 DigitalOut RXEnable(P5_1); //Used to Enable Reciever
tlyp 2:e4fcc385e824 85
tlyp 2:e4fcc385e824 86
tlyp 2:e4fcc385e824 87 volatile bool reading; //Check interrupt to dtermin if there is incoming data
tlyp 2:e4fcc385e824 88 volatile char dataIn[50]; //Hold incoming message
tlyp 2:e4fcc385e824 89 volatile int datacounter; //Count the incoming data
tlyp 2:e4fcc385e824 90
MI 0:41ed595f83f5 91
MI 0:41ed595f83f5 92 // *****************************************************************************
tlyp 2:e4fcc385e824 93 /**
tlyp 2:e4fcc385e824 94 * @brief Setup RTC with scaler set to 1 tick per ~ 1 ms
tlyp 2:e4fcc385e824 95 */
MI 1:8834bc22c2e7 96 void RTC_Setup()
MI 0:41ed595f83f5 97 {
tlyp 2:e4fcc385e824 98 rtc_cfg_t RTCconfig; //Declare RTC Object
tlyp 2:e4fcc385e824 99 RTCconfig.prescaler = RTC_PRESCALE_DIV_2_2; //~1ms per RTC tick
tlyp 2:e4fcc385e824 100 RTCconfig.prescalerMask = RTC_PRESCALE_DIV_2_2; //~1ms per RTC tick(0.97656ms)
MI 1:8834bc22c2e7 101 RTCconfig.snoozeCount = 0;
MI 1:8834bc22c2e7 102 RTCconfig.snoozeMode = RTC_SNOOZE_DISABLE;
MI 0:41ed595f83f5 103
tlyp 2:e4fcc385e824 104 RTC_Init(&RTCconfig); //initialize RTC with desired configuration
tlyp 2:e4fcc385e824 105
tlyp 2:e4fcc385e824 106 RTC_Start(); //Begin RTC
tlyp 2:e4fcc385e824 107 }
MI 0:41ed595f83f5 108
tlyp 2:e4fcc385e824 109 //*****************************************************************************
tlyp 2:e4fcc385e824 110 /**
tlyp 2:e4fcc385e824 111 * @brief Serial Intterupt to read incoming data from Reciever
tlyp 2:e4fcc385e824 112 */
tlyp 2:e4fcc385e824 113 void SerialCallback(){
tlyp 2:e4fcc385e824 114 wait_ms(1);
tlyp 2:e4fcc385e824 115 if (datacounter < 50){
tlyp 2:e4fcc385e824 116 while(uart.readable() && datacounter <= 50){
tlyp 2:e4fcc385e824 117 dataIn[datacounter] = uart.getc();
tlyp 2:e4fcc385e824 118 datacounter++;
tlyp 2:e4fcc385e824 119 }
tlyp 2:e4fcc385e824 120 }
MI 0:41ed595f83f5 121 }
MI 0:41ed595f83f5 122
tlyp 2:e4fcc385e824 123 //*****************************************************************************
tlyp 2:e4fcc385e824 124 /**
tlyp 2:e4fcc385e824 125 * @brief Shorten input data array to only one full transmission (eliminate excess and partial transactions)
tlyp 2:e4fcc385e824 126 * @param start - array position that contatins starting character ('b')
tlyp 2:e4fcc385e824 127 * @param input - Character array that holds the recorded data
tlyp 2:e4fcc385e824 128 * @param output - Output array that holds one packet of data
tlyp 2:e4fcc385e824 129 * @return 0 on success, 1 if the end character cannot be found
tlyp 2:e4fcc385e824 130 */
tlyp 2:e4fcc385e824 131 int buildArray(int start, volatile char *input,char *output){
tlyp 2:e4fcc385e824 132 int i = start+1;
tlyp 2:e4fcc385e824 133 int k = 0;
tlyp 2:e4fcc385e824 134 while(input[i] != 'c'){
tlyp 2:e4fcc385e824 135 output[k] = input[i];
tlyp 2:e4fcc385e824 136 i++;
tlyp 2:e4fcc385e824 137 k++;
tlyp 2:e4fcc385e824 138 if (i > 50){
tlyp 2:e4fcc385e824 139 return (1);
tlyp 2:e4fcc385e824 140 }
tlyp 2:e4fcc385e824 141 }
tlyp 2:e4fcc385e824 142 return(0);
tlyp 2:e4fcc385e824 143 }
tlyp 2:e4fcc385e824 144
tlyp 2:e4fcc385e824 145 //*****************************************************************************
tlyp 2:e4fcc385e824 146 /**
tlyp 2:e4fcc385e824 147 * @brief Intterupt for checking incoming data. When triggered, intterupt is added for reading incoming data, and flag is set for incoming data
tlyp 2:e4fcc385e824 148 */
tlyp 2:e4fcc385e824 149 void CheckUart(){
tlyp 2:e4fcc385e824 150 uart.attach(&SerialCallback);
tlyp 2:e4fcc385e824 151 CheckData.disable_irq();
tlyp 2:e4fcc385e824 152 reading = 1;
tlyp 2:e4fcc385e824 153 }
tlyp 2:e4fcc385e824 154
tlyp 2:e4fcc385e824 155 //******************************************************************************
tlyp 2:e4fcc385e824 156
MI 0:41ed595f83f5 157 int main(void)
MI 0:41ed595f83f5 158 {
tlyp 4:7320d2a40b92 159 //configure PMIC
MI 1:8834bc22c2e7 160 MAX32630FTHR pegasus(MAX32630FTHR::VIO_3V3);
tlyp 4:7320d2a40b92 161
tlyp 4:7320d2a40b92 162 uart.baud(9600); //baud rate set to 9600
MI 1:8834bc22c2e7 163
MI 0:41ed595f83f5 164 //check if starting at main because of LP0 wake-up
MI 1:8834bc22c2e7 165 if(LP_IsLP0WakeUp()) {
MI 1:8834bc22c2e7 166
MI 1:8834bc22c2e7 167 }
MI 0:41ed595f83f5 168 else {
MI 0:41ed595f83f5 169 //We did not wake up from sleep and this is first power-on
MI 1:8834bc22c2e7 170 //Only configure RTC the first time around
MI 1:8834bc22c2e7 171 RTC_Setup();
MI 0:41ed595f83f5 172 }
tlyp 3:4af4942a59f2 173
tlyp 4:7320d2a40b92 174 //LEDs on to indicate active mode
MI 0:41ed595f83f5 175 gLED = LED_ON;
MI 1:8834bc22c2e7 176 rLED = LED_ON;
MI 1:8834bc22c2e7 177 bLED = LED_ON;
tlyp 2:e4fcc385e824 178
tlyp 2:e4fcc385e824 179 CheckData.mode(PullNone); //Set Interrupt pin to no pull
tlyp 2:e4fcc385e824 180
MI 0:41ed595f83f5 181 while(1) {
MI 1:8834bc22c2e7 182 //Clear existing wake-up config
MI 1:8834bc22c2e7 183 LP_ClearWakeUpConfig();
MI 0:41ed595f83f5 184
MI 1:8834bc22c2e7 185 //Clear any event flags
MI 1:8834bc22c2e7 186 LP_ClearWakeUpFlags();
tlyp 2:e4fcc385e824 187
tlyp 2:e4fcc385e824 188 //hold down switch 1 to prevent the microcontroller from going into LP0
tlyp 2:e4fcc385e824 189 //Hold down Switch 1 in order to re-program device
tlyp 4:7320d2a40b92 190 while(sw2 == 0);
tlyp 2:e4fcc385e824 191
tlyp 2:e4fcc385e824 192 RXEnable = 1; //Enable the Reciever
tlyp 2:e4fcc385e824 193 wait_us(250); //Give the Reciever time to wake-up (250us on data Sheet)
tlyp 2:e4fcc385e824 194 datacounter = 0; //Reset Data Counter for transaction
tlyp 2:e4fcc385e824 195 reading = 0; //REset reading flag
tlyp 2:e4fcc385e824 196 CheckData.fall(&CheckUart); //Set falling edge intterupt to check for incoming data
tlyp 2:e4fcc385e824 197 wait_ms(5); //Wait for incoming data
tlyp 2:e4fcc385e824 198 printf("Checking for data\r\n");
tlyp 2:e4fcc385e824 199
tlyp 2:e4fcc385e824 200 //If CheckData intterupt is triggered, reading flag is set
tlyp 2:e4fcc385e824 201 if(reading == 1){
tlyp 2:e4fcc385e824 202
tlyp 2:e4fcc385e824 203 //Variables used for translation of incoming data
tlyp 2:e4fcc385e824 204 char dataOut[50];
tlyp 2:e4fcc385e824 205 uint16_t output[2];
tlyp 2:e4fcc385e824 206
tlyp 2:e4fcc385e824 207 wait_ms(50); //Wait for a full transimission of data
tlyp 2:e4fcc385e824 208 uart.attach(NULL); //Turn off intterupt on data Read
tlyp 2:e4fcc385e824 209 RXEnable = 0; //Turn off Receiver
tlyp 2:e4fcc385e824 210 int start = 0; //Variable to find start of packet
tlyp 2:e4fcc385e824 211
tlyp 2:e4fcc385e824 212 //Find starting position of full transmission
tlyp 2:e4fcc385e824 213 while(dataIn[start] != 'b' && start < datacounter){
tlyp 2:e4fcc385e824 214 start++;
tlyp 2:e4fcc385e824 215 }
tlyp 2:e4fcc385e824 216
tlyp 2:e4fcc385e824 217 //Make sure this is the starting character for transmission
tlyp 2:e4fcc385e824 218 if (dataIn[start] == 'b'){
MI 0:41ed595f83f5 219
tlyp 2:e4fcc385e824 220 //Condense array to just one data transmission
tlyp 2:e4fcc385e824 221 if (buildArray(start,dataIn,dataOut) == 0){
tlyp 2:e4fcc385e824 222 //Decrypt message with Symmetric Key and FEC to readible data
tlyp 2:e4fcc385e824 223 if (transRx.Decrypt(dataOut,output) == 1){
tlyp 2:e4fcc385e824 224 printf("Error reconstructing\r\n");
tlyp 2:e4fcc385e824 225 } //if
tlyp 2:e4fcc385e824 226
tlyp 2:e4fcc385e824 227 //Read Device ID and Type
tlyp 2:e4fcc385e824 228 char DeviceType = dataIn[start+1];
tlyp 2:e4fcc385e824 229 char DeviceID = dataIn[start+2];
tlyp 2:e4fcc385e824 230
tlyp 2:e4fcc385e824 231 //Print out the Device Type, ID, and Temperature
tlyp 2:e4fcc385e824 232 printf("Device Type: %c\r\n", DeviceType);
tlyp 2:e4fcc385e824 233 printf("Device ID: %i\r\n", DeviceID);
tlyp 2:e4fcc385e824 234 printf("data = %i\r\n",output[0]);
tlyp 2:e4fcc385e824 235 wait(1);
tlyp 2:e4fcc385e824 236
tlyp 2:e4fcc385e824 237 //Convert translated data into temperature data
tlyp 2:e4fcc385e824 238 float clesius = TempSensor.toCelsius(output[0]);
tlyp 2:e4fcc385e824 239 float fare = TempSensor.toFahrenheit(clesius);
tlyp 2:e4fcc385e824 240 printf("C = %f\r\n",clesius);
tlyp 2:e4fcc385e824 241 printf("F = %f\r\n",fare);
tlyp 2:e4fcc385e824 242 } //if
tlyp 2:e4fcc385e824 243 //End character cannot be found while condensing array (incomplete transmission)
tlyp 2:e4fcc385e824 244 else{
tlyp 2:e4fcc385e824 245 printf("No end character found\r\n");
tlyp 2:e4fcc385e824 246 } //else
tlyp 2:e4fcc385e824 247 } //if
tlyp 2:e4fcc385e824 248
tlyp 2:e4fcc385e824 249 //Reset dataIn array for next transmission
tlyp 2:e4fcc385e824 250 for (int i = 0;i<datacounter;i++){
tlyp 2:e4fcc385e824 251 dataIn[i] = 0;
tlyp 2:e4fcc385e824 252 } //for
tlyp 2:e4fcc385e824 253 }//if
tlyp 2:e4fcc385e824 254
tlyp 2:e4fcc385e824 255 //Turn off intterupt for checking data
tlyp 2:e4fcc385e824 256 CheckData.disable_irq();
tlyp 2:e4fcc385e824 257
MI 1:8834bc22c2e7 258 //configure wake-up on RTC compare 0
MI 1:8834bc22c2e7 259 //LP_ConfigRTCWakeUp(enable compare 0, enable compare 1, set prescale, set rollover)
MI 1:8834bc22c2e7 260 LP_ConfigRTCWakeUp(1, 0, 0, 0);
MI 1:8834bc22c2e7 261
tlyp 2:e4fcc385e824 262 RXEnable = 0; //Turn off Reciever
tlyp 2:e4fcc385e824 263
tlyp 2:e4fcc385e824 264 //disable unused PMIC rails to minimize power consumption
tlyp 2:e4fcc385e824 265 pegasus.max14690.ldo2SetMode(MAX14690::LDO_DISABLED);
tlyp 2:e4fcc385e824 266 pegasus.max14690.ldo3SetMode(MAX14690::LDO_DISABLED);
tlyp 2:e4fcc385e824 267
tlyp 2:e4fcc385e824 268 //Reset RTC value
tlyp 2:e4fcc385e824 269 RTC_SetCount(0);
tlyp 2:e4fcc385e824 270 gLED = LED_OFF;
tlyp 2:e4fcc385e824 271 rLED = LED_OFF;
tlyp 2:e4fcc385e824 272 bLED = LED_OFF;
MI 1:8834bc22c2e7 273
tlyp 3:4af4942a59f2 274 //set RTC to generate an interrupt 5 miliseconds from current value
tlyp 2:e4fcc385e824 275 RTC_SetCompare(0,500);
MI 1:8834bc22c2e7 276
MI 1:8834bc22c2e7 277 //clear comparison flag in the RTC registers
MI 1:8834bc22c2e7 278 RTC_ClearFlags(MXC_F_RTC_FLAGS_COMP0);
MI 0:41ed595f83f5 279
tlyp 2:e4fcc385e824 280 //Enter Deep Sleep Mode
MI 1:8834bc22c2e7 281 LP_EnterLP0();
MI 1:8834bc22c2e7 282
MI 1:8834bc22c2e7 283 //firmware will reset with no prior knowledge on wake-up
MI 0:41ed595f83f5 284 }
MI 0:41ed595f83f5 285 }