Hey everyone. I wanted to dive deep into registers and bare metal program just for fun, and i'm having a lot of trouble confirming that my TX device actually transmits any data.
As mentioned in the description, I'm expecting the FIFO_STATUS to be 1 at bit 4 that corrosponds to TX_EMPTY. Thanks to anyone willing to point me in the right direction 
I have tried both pulsing the CE pin and also just having it on the whole time.
Im not using auto ack. I tried to keep it as simple as can be...
Below here is the code for the TX device...
#define CONFIG 0x00
#define EN_AA 0x01
#define EN_RXADDR 0x02
#define SETUP_AW 0x03
#define SETUP_RETR 0x04
#define RF_CH 0x05
#define RF_SETUP 0x06
#define STATUS 0x07
#define OBSERVE_TX 0x08
#define CD 0x09
#define RX_ADDR_P0 0x0A
#define RX_ADDR_P1 0x0B
#define RX_ADDR_P2 0x0C
#define RX_ADDR_P3 0x0D
#define RX_ADDR_P4 0x0E
#define RX_ADDR_P5 0x0F
#define TX_ADDR 0x10
#define RX_PW_P0 0x11
#define RX_PW_P1 0x12
#define RX_PW_P2 0x13
#define RX_PW_P3 0x14
#define RX_PW_P4 0x15
#define RX_PW_P5 0x16
#define FIFO_STATUS 0x17
#define DYNPD 0x1C
#define FEATURE 0x1D
/* Instruction Mnemonics */
#define R_REGISTER 0x00
#define W_REGISTER 0x20
#define REGISTER_MASK 0x1F
#define ACTIVATE 0x50
#define R_RX_PL_WID 0x60
#define R_RX_PAYLOAD 0x61
#define W_TX_PAYLOAD 0xA0
#define W_ACK_PAYLOAD 0xA8
#define FLUSH_TX 0xE1
#define FLUSH_RX 0xE2
#define REUSE_TX_PL 0xE3
#define NOP 0xFF
#define dummyBYTE 0x00
#include <SPI.h>
#define CE_PIN 2
#define CSN_PIN 3
uint8_t TXDATAADRESS[5];
uint8_t TXadress[] = { 0xF4, 0xD3, 0xC3, 0xB3, 0xA3 };
uint8_t TXdata[32] = "Hello World\n";
void setup() {
pinMode(CE_PIN, OUTPUT);
pinMode(CSN_PIN, OUTPUT);
digitalWrite(CSN_PIN, HIGH);
Serial.begin(9600);
SPI.begin();
initializechip();
txmode(TXadress, 10);
uint8_t status = readRegister(STATUS);
Serial.println();
Serial.print("Status register is: ");
Serial.println(STATUS, HEX);
delay(2000);
}
void loop() {
uint8_t status = transmitdata(TXdata);
Serial.println(status);
}
void writeRegister(uint8_t REG, uint8_t VAL) {
digitalWrite(CSN_PIN, LOW);
SPI.transfer(W_REGISTER | REG);
SPI.transfer(VAL);
digitalWrite(CSN_PIN, HIGH);
uint8_t status = readRegister(REG);
Serial.println();
Serial.print("Status for: ");
Serial.println(REG, HEX);
Serial.println(status, BIN);
}
void writeRegisterMulti(uint8_t REG, uint8_t *DATA, int SIZE) {
digitalWrite(CSN_PIN, LOW);
SPI.transfer(W_REGISTER | REG);
for (int len = 0; len < SIZE; len++) {
SPI.transfer(DATA[len]);
}
digitalWrite(CSN_PIN, HIGH);
}
uint8_t readRegister(uint8_t REG) {
digitalWrite(CSN_PIN, LOW);
SPI.transfer(R_REGISTER | REG);
uint8_t registerstatus = SPI.transfer(dummyBYTE);
digitalWrite(CSN_PIN, HIGH);
return registerstatus;
}
void readRegisterMulti(uint8_t REG, uint8_t *DATA, int size) {
digitalWrite(CSN_PIN, LOW);
SPI.transfer(R_REGISTER | REG);
for (int len = 0; len < size; len++) {
DATA[len] = SPI.transfer(dummyBYTE);
}
digitalWrite(CSN_PIN, HIGH);
}
void sendcmd(uint8_t cmd) {
digitalWrite(CSN_PIN, LOW);
SPI.transfer(cmd);
digitalWrite(CSN_PIN, HIGH);
}
void initializechip() {
digitalWrite(CSN_PIN, HIGH);
writeRegister(CONFIG, 0); // config later
writeRegister(EN_AA, 0); // no auto ack
writeRegister(EN_RXADDR, 0); // disable all pipes
writeRegister(SETUP_AW, 0x03); // 5 byte address
writeRegister(SETUP_RETR, 0); // no retransmisson
writeRegister(RF_CH, 0); // later config
writeRegister(RF_SETUP, 0x0E); // power 0db 2 Mbps
}
void txmode(uint8_t *Adress, uint8_t channel) {
digitalWrite(CE_PIN, LOW);
digitalWrite(CSN_PIN, HIGH);
writeRegister(RF_CH, channel); // select channel
writeRegisterMulti(TX_ADDR, Adress, 5);
uint8_t config = readRegister(CONFIG);
config = config | (1 << 1);
writeRegister(CONFIG, config);
config = readRegister(CONFIG);
digitalWrite(CE_PIN, HIGH);
}
uint8_t transmitdata(uint8_t *data) {
digitalWrite(CSN_PIN, LOW);
SPI.transfer(W_TX_PAYLOAD);
for (int i = 0; i < 32; i++) {
SPI.transfer(data[i]);
}
digitalWrite(CSN_PIN, HIGH);
delayMicroseconds(15);
uint8_t fifostatus = readRegister(FIFO_STATUS);
Serial.println(fifostatus, BIN);
if ((fifostatus & (1 << 4)) && (!(fifostatus & (1 << 3)))) {
uint8_t cmdtosend = FLUSH_TX;
sendcmd(cmdtosend);
return 1;
}
return 0;
}