Helmut Schmücker / FtControlSet

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Dependencies:   NeedfulThings

FtControlSetReceiver.h@5:7ce37fae13ff, 2013-03-25 (annotated)

Committer:
humlet
Date:
Mon Mar 25 21:08:37 2013 +0000
Revision:
5:7ce37fae13ff
Parent:
4:c1517188f6ec 
introduction of NeedfulThings lib

Who changed what in which revision?

UserRevisionLine numberNew contents of line
humlet 0:a3a07eb0c1dd 1 #ifndef FTCONTROLSETRECEIVER_H
humlet 0:a3a07eb0c1dd 2 #define FTCONTROLSETRECEIVER_H
humlet 0:a3a07eb0c1dd 3
humlet 1:3904ef8c606e 4 #include "FtControlSetMessage.h"
humlet 0:a3a07eb0c1dd 5 #include "InterruptIn.h"
humlet 0:a3a07eb0c1dd 6 #include "FunctionPointer.h"
humlet 5:7ce37fae13ff 7 #include "TimeoutTweaked.h"
humlet 0:a3a07eb0c1dd 8
humlet 0:a3a07eb0c1dd 9 using namespace mbed;
humlet 0:a3a07eb0c1dd 10
humlet 0:a3a07eb0c1dd 11 /// Receiver interface for the fischertechnik IR control set
humlet 0:a3a07eb0c1dd 12 ///
humlet 0:a3a07eb0c1dd 13 /// An mbed port of the code found on this <A HREF="http://www.ftcommunity.de/wiki.php?action=show&topic_id=36">ft community WIKI page</a>
humlet 0:a3a07eb0c1dd 14 /// The ft IR remote control uses some kind of <A HREF="http://www.sbprojects.com/knowledge/ir/rcmm.php"> RC-MM Protocol </A>.
humlet 3:038f86bac6cc 15 /// When any of the controls is applied the remote control sends updates at a rate of at 1/120ms or 1/90ms depending on the senders frequency setting.
humlet 1:3904ef8c606e 16 /// Each message delivers the complete remote control status encoded into 30 bits.
humlet 3:038f86bac6cc 17 /// The structure of the message can be seen in FtControlSetMessage.h.
humlet 3:038f86bac6cc 18 /// The protocol uses Pulse Distance Modulation (PDM) with two bits (di-bit) per pulse, hence four different
humlet 0:a3a07eb0c1dd 19 /// distances. A transmission consists of 16 pulses (15 distances) for a total of 30 bits.
humlet 1:3904ef8c606e 20 ///
humlet 1:3904ef8c606e 21 /// I assume that the ft control set works fine with standard 38kHz IR detectors. I have used a CHQ0038 from a broken DVD Player.
humlet 1:3904ef8c606e 22 /// It can be onnected directly to the mebed: GND, VCC->3.3V and the signal line to any of the numbered mbed gpios.
humlet 3:038f86bac6cc 23 ///
humlet 3:038f86bac6cc 24 /// The PDM timing of the ft IR control set isn't that exact. Thus receive errors occur quite frequently. I am observing an error rate somewhere between
humlet 4:c1517188f6ec 25 /// 3% and 5%. This driver "ignores" up to 3 consecutive receive errors, i.e. it just indicates an error but still provides
humlet 4:c1517188f6ec 26 /// the last correctly received message, before it resets the message to zero after the fourth error.
humlet 4:c1517188f6ec 27 ///
humlet 4:c1517188f6ec 28 /// Some fluorescent energy saving lamp might disturb the transmision quite heavily.
humlet 3:038f86bac6cc 29
humlet 3:038f86bac6cc 30
humlet 0:a3a07eb0c1dd 31 class FtControlSetReceiver
humlet 0:a3a07eb0c1dd 32 {
humlet 0:a3a07eb0c1dd 33 InterruptIn m_pulseIRQ;
humlet 1:3904ef8c606e 34
humlet 3:038f86bac6cc 35 uint32_t m_rxBuffer; /// receive message buffer
humlet 4:c1517188f6ec 36 uint32_t m_nPulses; /// receive pulse counter (15 pulses per message)
humlet 4:c1517188f6ec 37 uint32_t m_timeOfLastEdge; /// signal edge time stamp memory
humlet 3:038f86bac6cc 38 uint8_t m_nOnes; /// number of received high bits for parity calculation
humlet 4:c1517188f6ec 39
humlet 4:c1517188f6ec 40 volatile uint32_t m_errorCount; /// counter of observed receive errors
humlet 4:c1517188f6ec 41 uint8_t m_nGracefullyIgnoredErrors; /// error counter that reset on successful message reception
humlet 1:3904ef8c606e 42
humlet 4:c1517188f6ec 43 volatile uint32_t m_lastMessage; /// last message received correctly
humlet 1:3904ef8c606e 44
humlet 4:c1517188f6ec 45 FunctionPointer m_callback; ///callback for user code that is called afetr successful message reception
humlet 1:3904ef8c606e 46
humlet 4:c1517188f6ec 47 TimeoutTweaked m_messageTimeout; /// Timeout for message reset when sender is inactive
humlet 4:c1517188f6ec 48 TimeoutTweaked m_receiveTimeout; /// receive timeout
humlet 4:c1517188f6ec 49 TimeoutTweaked m_recoverTimeout; /// error recovery timeout
humlet 4:c1517188f6ec 50
humlet 4:c1517188f6ec 51 static const uint32_t c_pulseWidthLimits[5]; /// di-bit discrimination times
humlet 3:038f86bac6cc 52 static const uint32_t c_pulseWidthDelta = 100;//101; /// di-bit discrimination pulse width delta
humlet 3:038f86bac6cc 53 static const uint32_t c_pulseWidthOffset = 795;//793; /// di-bit common pulse width base
humlet 3:038f86bac6cc 54 static const uint32_t c_maxPulseTime = c_pulseWidthOffset+7*c_pulseWidthDelta/2; /// reveive timeout
humlet 3:038f86bac6cc 55 static const uint32_t c_messageTimeout[2]; /// message timeout depends on selected sender frequency
humlet 4:c1517188f6ec 56 static const uint8_t c_errorsToBeGracefullyIgnored = 3; /// number of consecutive errors after which the message is reset
humlet 4:c1517188f6ec 57 static const uint32_t c_recoverTimeout = c_maxPulseTime; /// receiver is deactivated for this time after a receive error (IRQ burst suppression)
humlet 4:c1517188f6ec 58
humlet 3:038f86bac6cc 59 void pulseISR(); /// pulse handler
humlet 3:038f86bac6cc 60 void messageTimeoutISR(); /// message time out handler
humlet 3:038f86bac6cc 61 void recoverISR(); /// reactivates the pulse handler after recover timeout
humlet 1:3904ef8c606e 62
humlet 4:c1517188f6ec 63 void handleReceiveError();
humlet 4:c1517188f6ec 64
humlet 0:a3a07eb0c1dd 65 public:
humlet 4:c1517188f6ec 66
humlet 0:a3a07eb0c1dd 67 /// Create a receiver
humlet 1:3904ef8c606e 68 /// @parameter in: The pin the IR detector's message line is connected to
humlet 1:3904ef8c606e 69 FtControlSetReceiver(PinName in);
humlet 0:a3a07eb0c1dd 70
humlet 1:3904ef8c606e 71 /// get the last received message
humlet 3:038f86bac6cc 72 FtControlSetMessage getMessage()const {
humlet 4:c1517188f6ec 73 return FtControlSetMessage(m_lastMessage);
humlet 1:3904ef8c606e 74 };
humlet 1:3904ef8c606e 75
humlet 1:3904ef8c606e 76 /// get number of receive errors
humlet 1:3904ef8c606e 77 uint32_t getErrorCount()const {
humlet 1:3904ef8c606e 78 return m_errorCount;
humlet 1:3904ef8c606e 79 }
humlet 1:3904ef8c606e 80
humlet 1:3904ef8c606e 81 /// hook a call back into the receiver ISR e.g. for sending a RTOS message.
humlet 0:a3a07eb0c1dd 82 /// called on each update or receive error
humlet 4:c1517188f6ec 83 void setCallback(const FunctionPointer& callback) {
humlet 4:c1517188f6ec 84 m_callback=callback;
humlet 0:a3a07eb0c1dd 85 };
humlet 0:a3a07eb0c1dd 86 };
humlet 0:a3a07eb0c1dd 87
humlet 0:a3a07eb0c1dd 88
humlet 0:a3a07eb0c1dd 89 #endif
humlet 0:a3a07eb0c1dd 90
humlet 0:a3a07eb0c1dd 91
humlet 0:a3a07eb0c1dd 92
humlet 0:a3a07eb0c1dd 93
humlet 0:a3a07eb0c1dd 94
humlet 0:a3a07eb0c1dd 95
humlet 0:a3a07eb0c1dd 96