add I2C over BMS GPIO

send only and untested, for now

AMS_Master_Code/Core/Lib/ADBMS6830B_Driver/Core/Inc/ADBMS_CMD_MAKROS.h

@@ -77,9 +77,23 @@
 #define SRST   0x0027 //Soft reset
 
 #define DIAGN   0x0715 // Diagnos MUX and Poll Status
+
+
 #define WRCOMM  0x0721 // Write COMM Register Group
 #define RDCOMM  0x0722 // Read COMM Register Group
 #define STCOMM  0x0723 // Start I2C/SPI Communication
+#define I2C_SEND_START      0b0110 << 4
+#define I2C_SEND_STOP       0b0001 << 4
+#define I2C_SEND            0b0000 << 4
+#define I2C_SEND_NOTRANSFER 0b0111 << 4
+#define I2C_SEND_ACK        0b0000
+#define I2C_SEND_NACK       0b1000
+#define I2C_SEND_NACK_STOP  0b1001
+#define I2C_RECV_ACK        0b0111
+#define I2C_RECV_NACK       0b1111
+#define I2C_RECV_ACK_STOP   0b0001
+#define I2C_RECV_NACK_STOP  0b1001
+
 #define MUTE    0x0028 // Mute Discharge
 #define UNMUTE  0x0029 // Unmute Discharge
 

AMS_Master_Code/Core/Lib/ADBMS6830B_Driver/Core/Inc/ADBMS_LL_Driver.h

@@ -57,7 +57,10 @@ static inline HAL_StatusTypeDef __readCMD(uint16_t command, uint8_t * buffer, si
 #define readCMD(command, buffer, buflen) \
   __readCMD(command, buffer, buflen, CMD_BUFFER_SIZE(buflen))
 
-HAL_StatusTypeDef pollCMD(uint16_t command);
+HAL_StatusTypeDef __pollCMD(uint16_t command, uint8_t waitTime);
+
+#define pollCMD(command) \
+  __pollCMD(command, (N_BMS * 2) + 1) //poll is only valid after 2 * N_BMS clock cycles, +1 for safety, see datasheet page 55
 
 
 void mcuAdbmsCSLow();

AMS_Master_Code/Core/Lib/ADBMS6830B_Driver/Core/Src/ADBMS_Abstraction.c

@@ -316,3 +316,75 @@ HAL_StatusTypeDef amsReadCellVoltages(Cell_Module (*module)[N_BMS]) {
 
   return HAL_OK;
 }
+
+//Each selected BMS must have a corresponding address, and the data array for that BMS must be at least datalens[i] bytes long
+HAL_StatusTypeDef amsSendI2C(uint8_t addresses[static N_BMS], uint8_t * data[static N_BMS], uint8_t datalens[static N_BMS], uint32_t bms_mask) {
+  uint8_t buffer[CMD_BUFFER_SIZE(COMM_GROUP_SIZE)] = {};
+
+  //COMM register works in 3 bytes max per go, interleaved with control information
+
+  uint8_t max_datalen = 0;
+  for (size_t i = 0; i < N_BMS; i++) {
+    if (datalens[i] > max_datalen) {
+      max_datalen = datalens[i];
+    }
+  }
+
+  for (size_t i = 0; i < N_BMS; i++) {
+      size_t offset = BUFFER_BMS_OFFSET(i, COMM_GROUP_SIZE);
+
+      if (!(bms_mask & (1 << i))) {
+          buffer[offset + 0] = I2C_SEND_NOTRANSFER;
+          buffer[offset + 2] = I2C_SEND_NOTRANSFER;
+          buffer[offset + 4] = I2C_SEND_NOTRANSFER;
+          continue;
+      }
+  }
+
+  size_t packet_count = ((max_datalen + 1) / 3) + ((max_datalen + 1) % 3 != 0); //number of 3 byte packets needed to send all data
+
+  for (size_t i = 0; i < (packet_count * 3); i++) { //i - 1 is the number of data bytes sent so far (1 byte for the address)
+    for (size_t j = 0; j < N_BMS; j++) {
+      size_t offset = BUFFER_BMS_OFFSET(j, COMM_GROUP_SIZE);
+      if (!(bms_mask & (1 << j))) continue; //skip BMS that are not selected
+      
+      if (i == 0) {
+        buffer[offset + 0] = I2C_SEND_START;
+        buffer[offset + 1] = addresses[j];
+        continue;
+      }
+
+      //add data to the buffer
+
+      //case 1: the last group of 3 bytes contained the last data byte, so we need to send a stop
+      if (datalens[j] - (int)i == -1) {
+        buffer[offset + ((i % 3) * 2)] = I2C_SEND_STOP;
+        continue;
+      }
+
+      //case 2: we are more than one byte past the end, so we don't need to send any data
+      if (datalens[j] - (int)i < -1) {
+        buffer[offset + ((i % 3) * 2)] = I2C_SEND_NOTRANSFER;
+        continue;
+      }
+
+      //case 3: we are still sending data
+      buffer[offset + ((i % 3) * 2)]     = I2C_SEND;
+      buffer[offset + ((i % 3) * 2) + 1] = data[j][i - 1];
+    }
+
+    //send the data
+    if (i % 3 == 0 && i != 0) {
+      CHECK_RETURN(writeCMD(WRCOMM, buffer, COMM_GROUP_SIZE));
+
+      __pollCMD(STCOMM, 72); //wait 72 cycles for the I2C transfer to complete (datasheet page 43)
+                                               //TODO: not sure if this is correct for a daisy chain
+    }
+  }
+
+  //send the last packet
+  CHECK_RETURN(writeCMD(WRCOMM, buffer, COMM_GROUP_SIZE));
+  __pollCMD(STCOMM, 72);
+
+  return HAL_OK;
+}

AMS_Master_Code/Core/Lib/ADBMS6830B_Driver/Core/Src/ADBMS_LL_Driver.c

@@ -212,17 +212,15 @@ HAL_StatusTypeDef ___readCMD(uint16_t command, uint8_t * buffer, size_t arglen)
   return HAL_OK;
 }
 
-//check poll command - no data PEC sent back
+//check poll command - no data PEC sent back, waitTime is in SPI clock cycles
-HAL_StatusTypeDef pollCMD(uint16_t command) {
+HAL_StatusTypeDef __pollCMD(uint16_t command, uint8_t waitTime) {
-  uint8_t buffer[4 + (N_BMS * 2) + 1] = {}; //poll is only valid after 2 * N_BMS clock cycles (datasheet page 55)
+  uint8_t buffer[4 + (waitTime / 8) + 1] = {}; //8 cycles per byte, +1 as we round up 
-                                            //being conservative and adding 1 byte for the poll response
-
   buffer[0] = (command >> 8) & 0xFF;
   buffer[1] = (command) & 0xFF;
   calculateCommandPEC(buffer, 4);
 
   mcuAdbmsCSLow();
-  HAL_StatusTypeDef status = mcuSPITransmitReceive(buffer, buffer, 4 + (N_BMS * 2) + 1);
+  HAL_StatusTypeDef status = mcuSPITransmitReceive(buffer, buffer, sizeof buffer);
   mcuAdbmsCSHigh();
 
   if (status != HAL_OK) return status;