K Andres / Mbed 2 deprecated SCIboard

SCIboard(TM): mbed base board data logger - Altimeter: MPL3115A2 - Accelerometer: LSM303DLHC - Gyro: L3G4200D - 4 High Current MOSFET switches

Dependencies:   mbed

Product Description

SCIboard will take your model rocketry, science, or engineering project to new heights with a complete 10-Degree-Of-Freedom (10-DOF) Inertial Measurement Unit (IMU), 4 high current MOSFET switches, PWM interface (RC servos), USB (memory sticks or BlueTooth) and interfaces for GPS and an XBee® RF module. The SCIboard is an mbed base board ideal for use in college and high school science labs, science fair projects, high power model rocketry, model airplanes, and near space balloon projects. SCIboard is also designed for Open Source software so you can customize the application. Example applications include high power model rocketry, near space balloon projects, and R/C airplanes/quadcopters. While SCIboard requires some basic electronics and software knowledge, it combines multiple breakout boards into a single base board which improves reliability, especially in high g environments such as in model rocketry. Available on Amazon. Search on "SCIboard".

• Dimensions: 1.5 x 3.8 inches (3.8 x 9.7 cm)
• Weight: 0.8 ounces (24 g)

10-DOF Inertial Measurement Unit

Going beyond just the 6 degrees of freedom afforded by a 3-axis accelerometer and 3-axis gyro, SCIboard includes an additional 3-axis magnetometer, and highly accurate altimeter / atmospheric pressure sensor. Sensors provide digital measurements over an I2C shared bus (p27 and p28).

Precision Altimeter

(Freescale Semiconductor – MPL3115A2) MEMS pressure sensor with 24-bit Analog-to-Digital Converter (ADC) employs temperature compensation resulting in fully compensated 20-bit pressure/altitude measurements (resolution down to 1 foot).

• Pressure range: 50 – 110 kPa.
• Pressure reading noise: 1.5 Pa RMS over -10 to +70° C. Conversion rate: up to 100 Hz.
• 12-bit temperature sensor measurement range: -40 to +85° C.

3-Axis MEMS Accelerometer

(STMicroelectronics – LSM303DLHC) The sensor measures linear acceleration. Pointing any axis to the earth will apply 1 g in that axis when stationary.

• Selectable full scale range: +/-2 g to +/-16 g.
• Sensitivity: 1 – 12 mg/LSB depending on full scale range.
• Zero-g level offset: +/-60 mg.
• Acceleration noise density: 220 micro-g/sqrt(Hz).
• Operating temp range: -40 to +85° C.
• Conversion rate up to 400 Hz.

3-Axis Ultra-Stable MEMS Gyroscope

(STMicroelectronics – L3G4200D) A gyroscope is an angular rate sensor.

• Selectable full scale ranges: 250/500/2000 degrees per second (DPS).
• Resolution: 16-bit.
• Bandwidth: user selectable.
• Sensitivity: 8.75/17.50/70 milli-degrees per second/LSB.
• Nonlinearity: 0.2% full scale
• Rate noise density: 0.03 DPS/sqrt(Hz).
• Operating temp range: -40 to +85°C.

Digital I/O

4 MOSFET switches are included. They provide 6-amperes momentary current sinking. Example uses include high power strobes, and lights for night launches or buzzers for location. Switches can be activated at apogee or prior to landing for model rocketry. A continuity check through an analog to digital converter allows verification of circuit continuity before launch. A piezoelectric buzzer provides software control for audible alert and low battery voltage measurement.

Host USB Type-A with 5.0 Vdc regulator

USB Type-A connector wired as a host controller provides regulated 5 volt power from a battery. A variety of USB devices from memory sticks, Bluetooth, and Wi-Fi can be used with multiple software projects from the mbed web site.

XBee® and XBee-PRO® Modules

The XBee-PRO® interface supports multiple different XBee and XBee-PRO modules such as Wi-Fi, ZigBee, 802.15.4, Bluetooth, and longer range 900 MHz RF Modules. Compatible modules are Roving Networks and Digi-International. SCIboard provides dual 10 pin headers with regulated 3.3 volt power (from p40) and serial UART (Tx=p9/Rx=p10). Alternatively if the headers are not installed, the serial port may be connected to a SMS cell phone evaluation module. Since the 3.3 volt provided to XBee modules is from the mbed regulator, the user is responsible for power calculations. Testing was done with RN-XV and a 9-volt battery but higher battery voltages or higher current XBee modules could overheat the 3.3 volt regulator on the mbed. When using XBee modules, the user may need to perform hard/soft iron calibration if using the magnetometer.

Interface for GPS

SCIboard provides a serial UART interface for GPS receivers. It also provides 3.3 and 5.0 Vdc for power and Vbat (battery not included). PCB has 0.1” holes for soldered cable or header of your choice. This provides flexibility to use a variety of GPS modules.

Interface for Ethernet Cable

PCB has 0.1” interface for an Ethernet cable of your choice of Ethernet magnetics interface with LEDs. For Ethernet direct wire, use RD-, RD+, TD+, and TD-. For magnetics, several 3.3 Vdc and Grounds are provided allowing easy interfacing. For both LEDs a 160 ohm resistor is provided. Both LEDs share the 2 PWMs out.

Interface for PWM RC Servos

SCIboard provides a Pulse Width Modulation (PWM) header for RC servo motors. Up to 6 PWM servos can be controlled. Terminal block is provided for separate servo power source if desired. If the user chooses to not install the headers, the PCB has 0.1” spacing thru-holes for 3-pin R/C servos. (Pins 21 – 26)

Applications

A 10-Degree-Of-Freedom Inertial Measurement Unit (IMU) can be used to measure distance traveled, velocity, acceleration, attitude (yaw, pitch, and roll), and attitude rate. When combined with a GPS, SCIboard will provide a GPS aided inertial navigation solutions. The PWM can be used to control a camera attached to a servo motor. This enables near space projects to point the camera up at the weather balloon, horizontally at the earth’s horizon, and down directly at the earth.

1. College and high school science labs
2. Science Fairs
3. High Power Model Rocketry
4. Near Space Balloons
5. Quadcopters
6. R/C Airplanes
7. R/C Helicopter

Processor Board Support (Direct Pin-Out compatible)

• mbed LPC1768
• mbed LPC11U24
• Embedded Artists LPCexpresso LPC1769

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SCIboard_ubloxGps.cpp	Sun Apr 06 19:03:29 2014 +0000
@@ -0,0 +1,211 @@
+/* SCIboard(TM) SCIboard_ubloxGps.cpp
+Copyright (c) 2013 K. Andres
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include "SCIboard_ubloxGps.h"
+
+#define SYNC_CHAR_1 0xB5
+#define SYNC_CHAR_2 0x62
+
+#define MAX_UBLOX_PACKET_SIZE  512
+
+// UBX Class IDs
+#define NAV_CLASS_ID    0x01    // Navigation
+#define RXM_CLASS_ID    0x02    // Receiver
+#define INF_CLASS_ID    0x04    // Information
+#define ACK_CLASS_ID    0x05    // Ack/Nack
+#define CFG_CLASS_ID    0x06    // Configuration input
+#define MON_CLASS_ID    0x0A    // Monitoring messages
+#define AID_CLASS_ID    0x0B    // AssistNow Aiding
+#define TIM_CLASS_ID    0x0D    // Timing
+#define ESF_CLASS_ID    0x10    // External Sensor Fusion
+
+
+// Default - messages to keep
+#define NAV_SOL         0x06    // TOWms, week, ECEF
+
+// Turn ON some messages
+#define NAV_SVINFO      0x30
+
+// Turn off some default messages
+#define NAV_POSLLH      0x02
+#define NAV_STATUS      0x03
+#define NAV_VELNED      0x12
+
+#define TIM_TP          0x01
+#define TIM_VRFY        0x06
+
+
+extern Serial pc;
+extern Serial gps;
+
+void ublox_gps_callback();
+
+#define UBLOX_BUF_SIZE  2048
+
+// Input buffer
+char ublox_msg_in[UBLOX_BUF_SIZE];
+int nextin, nextout;
+
+// Output buffer
+char ublox_msg_out[UBLOX_BUF_SIZE];
+char ublox_cnt;
+char ublox_msg_out_flag;
+
+char packetState;
+int ublox_size;
+
+#define UBLOX_MSG_CLASS     2       // field within msg
+#define UBLOX_MSG_ID        3
+
+void ubloxMsgRate(char msgclass, char id, char rate);
+void ubloxBaudRate(void);
+
+SCIboard_ubloxGps::SCIboard_ubloxGps() {
+    ublox_cnt = 0;
+    ublox_msg_out_flag = 0;
+    nextin=nextout=0;
+    packetState=0;
+}
+
+FILE *ublox_fp=NULL;
+
+void SCIboard_ubloxGps::gps_startup(void) {
+    gps.baud(38400);
+    wait(.01);
+    
+    if(ublox_fp==NULL) {
+        ublox_fp = fopen("/local/GPS.txt", "w");  // Open "GPS.txt" on the local file system for appending
+    }
+
+    // Turn off some of the default messages
+    ubloxMsgRate(TIM_CLASS_ID, TIM_TP, 0);
+    ubloxMsgRate(TIM_CLASS_ID, TIM_VRFY, 0);
+    ubloxMsgRate(NAV_CLASS_ID, NAV_VELNED, 0);
+    ubloxMsgRate(NAV_CLASS_ID, NAV_STATUS, 0);
+    ubloxMsgRate(NAV_CLASS_ID, NAV_POSLLH, 0);
+
+    // Turn on some messages
+    ubloxMsgRate(NAV_CLASS_ID, NAV_SOL, 4);         // Change rate to once per second
+    ubloxMsgRate(NAV_CLASS_ID, NAV_SVINFO, 8);      // Change rate to once per 2 seconds
+    
+    void ubloxBaudRate();    // Drop baud rate
+    
+    gps.attach(&ublox_gps_callback);
+}
+
+void SCIboard_ubloxGps::gps_close(void) {
+    gps.attach(NULL);
+    wait(0.01);
+    
+    if(nextin) {
+        if(ublox_fp!=NULL) {
+            memcpy(ublox_msg_out, ublox_msg_in, nextin);
+            fwrite(ublox_msg_out, nextin, 1, ublox_fp);
+        }  
+        nextin=0;
+    }
+
+    if(ublox_fp!=NULL) {
+        fclose(ublox_fp);
+        ublox_fp=NULL;
+    }
+}
+
+
+void ublox_gps_callback() {
+    // Note: you need to actually read from the serial to clear the RX interrupt
+    __disable_irq();
+    ublox_msg_in[nextin++] = gps.getc();
+    __enable_irq();
+
+    if(nextin>=sizeof(ublox_msg_in)) {
+        nextin=0;
+        if(ublox_fp!=NULL) {
+            memcpy(ublox_msg_out, ublox_msg_in, sizeof(ublox_msg_in));
+            fwrite(ublox_msg_out, sizeof(ublox_msg_out), 1, ublox_fp);
+        }  
+    }
+}
+
+
+// Change message rate or turn off message
+void ubloxMsgRate(char msgclass, char id, char rate) {
+    unsigned char chkA=0, chkB=0;
+    int n;
+    uint8_t buf[] = {
+        6,               // CLASS: CFG
+        1,               // ID: MSG
+        8,               // LENGTH
+        0,               // LENGTH
+        msgclass,
+        id,
+        0,
+        rate,
+        0, 0, 0, 0};
+        
+    gps.putc(SYNC_CHAR_1);
+    gps.putc(SYNC_CHAR_2);
+    
+    for(n=0; n<sizeof(buf); n++) {
+        gps.putc(buf[n]);
+        chkA += buf[n];
+        chkB += chkA;    
+    }
+    
+    gps.putc(chkA);
+    gps.putc(chkB);
+}
+
+
+// Change message baud rate --------------------------------
+// Baud rate divisors
+// 0, 0, 0x96, 0            // 38,400
+// 0, 0, 0x4B, 0            // 19,200
+// 0, 0x80, 0x25, 0         //  9,600
+// 0, 0xC0, 0x12, 0         //  4,800
+
+void ubloxBaudRate(void) {
+    unsigned char chkA=0, chkB=0;
+    int n;
+    uint8_t buf[] = {
+        6, 0,            // CLASS/id: CFG-PRT
+        0x14, 0,         // LENGTH     
+        01, 0,
+        0, 0, 0xD0, 8, 0, 0, 0xC0, 0x12,
+        0, 0, 7, 0, 1, 0, 0, 0,
+        0, 0};
+
+    gps.putc(SYNC_CHAR_1);
+    gps.putc(SYNC_CHAR_2);
+    
+    for(n=0; n<sizeof(buf); n++) {
+        gps.putc(buf[n]);
+        chkA += buf[n];
+        chkB += chkA;    
+    }
+    
+    gps.putc(chkA);
+    gps.putc(chkB);
+
+    wait(.500);
+    gps.baud(4800);
+}