From 43764a1f9687a5fc18c6f96a0831473c32ff39cc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Grome=C5=A1?= <jgromes@users.noreply.github.com>
Date: Mon, 23 Jul 2018 11:19:34 +0200
Subject: [PATCH] Added SPI verification after write

---
 src/Module.cpp | 72 +++++++++++++++++++++++++++++++++++---------------
 src/Module.h   | 11 ++++----
 2 files changed, 56 insertions(+), 27 deletions(-)

diff --git a/src/Module.cpp b/src/Module.cpp
index b6ce558a..229ee5b7 100644
--- a/src/Module.cpp
+++ b/src/Module.cpp
@@ -18,7 +18,7 @@ Module::Module(int cs, int tx, int rx, int int0, int int1) {
   ModuleSerial = new SoftwareSerial(_tx, _rx);
 }
 
-uint8_t Module::init(uint8_t interface, uint8_t gpio) {
+void Module::init(uint8_t interface, uint8_t gpio) {
   DEBUG_BEGIN(9600);
   DEBUG_PRINTLN();
   
@@ -97,7 +97,7 @@ bool Module::ATgetResponse() {
   return(false);
 }
 
-uint8_t Module::SPIgetRegValue(uint8_t reg, uint8_t msb, uint8_t lsb) {
+int16_t Module::SPIgetRegValue(uint8_t reg, uint8_t msb, uint8_t lsb) {
   if((msb > 7) || (lsb > 7) || (lsb > msb)) {
     return(ERR_INVALID_BIT_RANGE);
   }
@@ -107,24 +107,64 @@ uint8_t Module::SPIgetRegValue(uint8_t reg, uint8_t msb, uint8_t lsb) {
   return(maskedValue);
 }
 
-uint8_t Module::SPIreadRegisterBurst(uint8_t reg, uint8_t numBytes, uint8_t* inBytes) {
-  digitalWrite(_cs, LOW);
-  SPI.transfer(reg | SPI_READ);
-  for(uint8_t i = 0; i < numBytes; i++) {
-    inBytes[i] = SPI.transfer(reg);
+int16_t Module::SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb, uint8_t lsb) {
+  if((msb > 7) || (lsb > 7) || (lsb > msb)) {
+    return(ERR_INVALID_BIT_RANGE);
   }
-  digitalWrite(_cs, HIGH);
+  
+  uint8_t currentValue = SPIreadRegister(reg);
+  uint8_t mask = ~((0b11111111 << (msb + 1)) | (0b11111111 >> (8 - lsb)));
+  uint8_t newValue = (currentValue & ~mask) | (value & mask);
+  SPIwriteRegister(reg, newValue);
+  
+  // some registers need a bit of time to process the change
+  // e.g. SX127X_REG_OP_MODE
+  delay(5);
+  
+  // check if the write was successful
+  uint8_t readValue = SPIreadRegister(reg);
+  if(readValue != newValue) {
+    DEBUG_PRINTLN();
+    DEBUG_PRINT_STR("address:\t0x");
+    DEBUG_PRINTLN_HEX(reg);
+    DEBUG_PRINT_STR("bits:\t\t");
+    DEBUG_PRINT(msb);
+    DEBUG_PRINT(' ');
+    DEBUG_PRINTLN(lsb);
+    DEBUG_PRINT_STR("value:\t\t0b");
+    DEBUG_PRINTLN_BIN(value);
+    DEBUG_PRINT_STR("current:\t0b");
+    DEBUG_PRINTLN_BIN(currentValue);
+    DEBUG_PRINT_STR("mask:\t\t0b");
+    DEBUG_PRINTLN_BIN(mask);
+    DEBUG_PRINT_STR("new:\t\t0b");
+    DEBUG_PRINTLN_BIN(newValue);
+    DEBUG_PRINT_STR("read:\t\t0b");
+    DEBUG_PRINTLN_BIN(readValue);
+    DEBUG_PRINTLN();
+    
+    return(ERR_SPI_WRITE_FAILED);
+  }
+  
   return(ERR_NONE);
 }
 
-uint8_t Module::SPIreadRegisterBurstStr(uint8_t reg, uint8_t numBytes, char* inBytes) {
+void Module::SPIreadRegisterBurst(uint8_t reg, uint8_t numBytes, uint8_t* inBytes) {
+  digitalWrite(_cs, LOW);
+  SPI.transfer(reg | SPI_READ);
+  for(uint8_t i = 0; i < numBytes; i++) {
+    inBytes[i] = SPI.transfer(reg);
+  }
+  digitalWrite(_cs, HIGH);
+}
+
+void Module::SPIreadRegisterBurstStr(uint8_t reg, uint8_t numBytes, char* inBytes) {
   digitalWrite(_cs, LOW);
   SPI.transfer(reg | SPI_READ);
   for(uint8_t i = 0; i < numBytes; i++) {
     inBytes[i] = SPI.transfer(reg);
   }
   digitalWrite(_cs, HIGH);
-  return(ERR_NONE);
 }
 
 uint8_t Module::SPIreadRegister(uint8_t reg) {
@@ -138,18 +178,6 @@ uint8_t Module::SPIreadRegister(uint8_t reg) {
   return(inByte);
 }
 
-uint8_t Module::SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb, uint8_t lsb) {
-  if((msb > 7) || (lsb > 7) || (lsb > msb)) {
-    return(ERR_INVALID_BIT_RANGE);
-  }
-  
-  uint8_t currentValue = SPIreadRegister(reg);
-  uint8_t mask = ~((0b11111111 << (msb + 1)) | (0b11111111 >> (8 - lsb)));
-  uint8_t newValue = (currentValue & ~mask) | (value & mask);
-  SPIwriteRegister(reg, newValue);
-  return(ERR_NONE);
-}
-
 void Module::SPIwriteRegisterBurst(uint8_t reg, uint8_t* data, uint8_t numBytes) {
   digitalWrite(_cs, LOW);
   SPI.transfer(reg | SPI_WRITE);
diff --git a/src/Module.h b/src/Module.h
index d5d1012a..1f7c8e69 100644
--- a/src/Module.h
+++ b/src/Module.h
@@ -20,19 +20,20 @@ class Module {
     uint32_t baudrate = 9600;
     const char* AtLineFeed = "\r\n";
     
-    uint8_t init(uint8_t interface, uint8_t gpio);
+    void init(uint8_t interface, uint8_t gpio);
     
     void ATemptyBuffer();
     bool ATgetResponse();
     bool ATsendCommand(const char* cmd);
     bool ATsendData(uint8_t* data, uint32_t len);
     
-    uint8_t SPIgetRegValue(uint8_t reg, uint8_t msb = 7, uint8_t lsb = 0);
-    uint8_t SPIreadRegisterBurst(uint8_t reg, uint8_t numBytes, uint8_t* inBytes);
-    uint8_t SPIreadRegisterBurstStr(uint8_t reg, uint8_t numBytes, char* str);
+    int16_t SPIgetRegValue(uint8_t reg, uint8_t msb = 7, uint8_t lsb = 0);
+    int16_t SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb = 7, uint8_t lsb = 0);
+    
+    void SPIreadRegisterBurst(uint8_t reg, uint8_t numBytes, uint8_t* inBytes);
+    void SPIreadRegisterBurstStr(uint8_t reg, uint8_t numBytes, char* str);
     uint8_t SPIreadRegister(uint8_t reg);
     
-    uint8_t SPIsetRegValue(uint8_t reg, uint8_t value, uint8_t msb = 7, uint8_t lsb = 0);
     void SPIwriteRegisterBurst(uint8_t reg, uint8_t* data, uint8_t numBytes);
     void SPIwriteRegisterBurstStr(uint8_t reg, const char* data, uint8_t numBytes);
     void SPIwriteRegister(uint8_t reg, uint8_t data);