/*
* Copyright (c) 2021, Texas Instruments Incorporated
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Texas Instruments Incorporated nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "ti_msp_dl_config.h"
/* Maximum size of TX packet */
#define I2C_TX_MAX_PACKET_SIZE (16)
/* Maximum size of RX packet */
#define I2C_RX_MAX_PACKET_SIZE (16)
/* Commands for the ADC sampling */
#define SAMPLE_ADC (0x01)
#define SEND_RESULTS (0x02)
#define SAMPLE_SEND_RESULTS (0x03)
/* Data sent to Controller in response to Read transfer, default set to 0xAA */
uint8_t gTxPacket[I2C_TX_MAX_PACKET_SIZE] = {0xAA};
/* Counters for TX length and bytes sent */
uint32_t gTxLen, gTxCount;
/* Data received from Controller during a Write transfer */
uint8_t gRxPacket[I2C_RX_MAX_PACKET_SIZE];
/* Counters for TX length and bytes sent */
uint32_t gRxLen, gRxCount, gCommandCount;
/* Boolean to know when a stop command was issued */
bool gStopReceived = false;
/* ADC variables:
* gADCResult is the adc result taken from the Memory Register
* NumberOfADCSamples is the count of total ADC samples to keep track for the gTxResult buffer
*/
uint16_t gADCResult;
uint8_t gNumberOfADCSamples = 0;
bool gCheckADC = false;
/* Process Command will take the command from the I2C Rx and parse which command is to be issued */
void processCommand(uint8_t cmd);
/* ADC Process will start the ADC and separate the ADC result into 8 bits to place into the Tx Packet buffer. */
void ADCProcess();
int main(void)
{
SYSCFG_DL_init();
/* Set LED to indicate start of transfer */
DL_GPIO_setPins(GPIO_LEDS_PORT, GPIO_LEDS_USER_LED_1_PIN);
/* Reset variables for the Tx, these are used in the I2C ISR */
gTxCount = 0;
gTxLen = 0;
DL_I2C_enableInterrupt(I2C_INST, DL_I2C_INTERRUPT_TARGET_TXFIFO_TRIGGER);
/* Initialize variables to receive data inside RX ISR */
gRxCount = 0;
gRxLen = I2C_RX_MAX_PACKET_SIZE;
NVIC_EnableIRQ(I2C_INST_INT_IRQN);
NVIC_EnableIRQ(ADC12_0_INST_INT_IRQN);
while (1)
{
/* Sleep until the stop command is given from the I2C Controller */
while(gStopReceived == false)
__WFE();
gStopReceived = false;
/* Process given commands */
for(uint16_t i = 0; i < gCommandCount; i++){
processCommand(gRxPacket[i]);
}
gCommandCount = 0;
}
}
/* Process the command given */
void processCommand(uint8_t cmd){
switch(cmd){
/* Sample the ADC */
case SAMPLE_ADC:
ADCProcess();
break;
/* Add 2 to the Tx Length, this equates to one more full result added to the TX transmission */
case SEND_RESULTS:
gTxLen += 2;
break;
/* Sample the ADC and increment the Tx Length. */
case SAMPLE_SEND_RESULTS:
ADCProcess();
gTxLen += 2;
break;
default:
break;
}
}
/* Start the ADC process of sampling and storing into the TxPacket Buffer */
void ADCProcess(){
/* Start the ADC Sampling */
DL_ADC12_startConversion(ADC12_0_INST);
/* Sleep until the ADC sampling and conversion is finished, then reset the boolean */
while(gCheckADC == false){
__WFI();
}
gCheckADC = false;
/* Get the ADC result and place the upper byte and lower byte into the TxPacket, upper byte first */
gADCResult = DL_ADC12_getMemResult(ADC12_0_INST, DL_ADC12_MEM_IDX_0);
gTxPacket[gNumberOfADCSamples*2] = (uint8_t)((gADCResult >> 8) & 0xFF);
gTxPacket[gNumberOfADCSamples*2 + 1] = (uint8_t)(gADCResult & 0xFF);
/* Make sure the number of ADC samples does not go over the TxPacket size, if it does next sample will overwrite */
gNumberOfADCSamples++;
if(gNumberOfADCSamples*2 + 1 > I2C_TX_MAX_PACKET_SIZE)
{
gNumberOfADCSamples = 0;
}
DL_ADC12_enableConversions(ADC12_0_INST);
}
void ADC12_0_INST_IRQHandler(void) {
switch (DL_ADC12_getPendingInterrupt(ADC12_0_INST)) {
case DL_ADC12_IIDX_MEM0_RESULT_LOADED:
gCheckADC = true;
break;
default:
break;
}
}
void I2C_INST_IRQHandler(void)
{
static bool commandReceived = false;
switch (DL_I2C_getPendingInterrupt(I2C_INST)) {
case DL_I2C_IIDX_TARGET_START:
/* Initialize RX or TX after Start condition is received */
gTxCount = 0;
gRxCount = 0;
commandReceived = false;
/* Flush TX FIFO to refill it */
DL_I2C_flushTargetTXFIFO(I2C_INST);
break;
case DL_I2C_IIDX_TARGET_RXFIFO_TRIGGER:
/* Store received commands in buffer */
commandReceived = true;
while (DL_I2C_isTargetRXFIFOEmpty(I2C_INST) != true) {
if (gRxCount < gRxLen) {
gRxPacket[gRxCount++] = DL_I2C_receiveTargetData(I2C_INST);
} else {
/* Prevent overflow and just ignore data */
DL_I2C_receiveTargetData(I2C_INST);
}
}
break;
case DL_I2C_IIDX_TARGET_TXFIFO_TRIGGER:
/* Fill TX FIFO with ADC Results */
if (gTxCount < gTxLen) {
gTxCount += DL_I2C_fillTargetTXFIFO(
I2C_INST, &gTxPacket[gTxCount], (gTxLen - gTxCount));
} else {
/*
* Fill FIFO with 0xAA if more data is requested than
* expected gTxLen
*/
while (DL_I2C_transmitTargetDataCheck(I2C_INST, 0xAA) != false)
;
}
break;
case DL_I2C_IIDX_TARGET_STOP:
/* If commands were received, set the command count to RxCount and reset fifo */
if (commandReceived == true) {
gCommandCount = gRxCount;
commandReceived = false;
DL_I2C_flushTargetTXFIFO(I2C_INST);
}
/* Set Stop Received to true to allow the main loop to proceed */
gStopReceived = true;
/* Toggle LED to indicate successful RX or TX */
DL_GPIO_togglePins(GPIO_LEDS_PORT, GPIO_LEDS_USER_LED_1_PIN);
break;
default:
break;
}
}
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