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DShotRMT
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...cosmetics

This commit is contained in:
Wastl Kraus 2021-07-17 06:40:21 +02:00
parent 0d2bf9e117
commit 11433bc125
2 changed files with 22 additions and 41 deletions
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45
src/DShotRMT.cpp
View File

@ -95,16 +95,10 @@ bool DShotRMT::begin(dshot_mode_t dshot_mode, bool is_bidirectional) {
rmt_config(&rmt_dshot_config);
// ...essential step, return the result
auto init_failed = rmt_driver_install(rmt_dshot_config.channel, 0, 0);
// ...because esp_err_t returns more than true or false
if (init_failed != 0) {
return true;
} else {
return false;
}
return rmt_driver_install(rmt_dshot_config.channel, 0, 0);
}
//´...the config part is done, now the calculating and sending part
void DShotRMT::send_dshot_value(uint16_t throttle_value, telemetric_request_t telemetric_request) {
dshot_packet_t dshot_rmt_packet = { };
@ -116,17 +110,12 @@ void DShotRMT::send_dshot_value(uint16_t throttle_value, telemetric_request_t te
throttle_value = DSHOT_THROTTLE_MAX;
}
if (dshot_config.bidirectional) {
// ...implement bidirectional mode
} else {
// ...packets are the same for bidirectional mode
dshot_rmt_packet.throttle_value = throttle_value;
dshot_rmt_packet.telemetric_request = telemetric_request;
dshot_rmt_packet.checksum = this->calc_dshot_chksum(dshot_rmt_packet);
output_rmt_data(dshot_rmt_packet);
}
}
// ...get all setup data about current mode
@ -144,21 +133,20 @@ rmt_item32_t* DShotRMT::encode_dshot_to_rmt(uint16_t parsed_packet) {
if (parsed_packet & 0b1000000000000000) {
// set one
dshot_tx_rmt_item[i].duration0 = dshot_config.ticks_one_high;
dshot_tx_rmt_item[i].level0 = 1;
dshot_tx_rmt_item[i].duration1 = dshot_config.ticks_one_low;
dshot_tx_rmt_item[i].level1 = 0;
}
else {
// set zero
dshot_tx_rmt_item[i].duration0 = dshot_config.ticks_zero_high;
dshot_tx_rmt_item[i].level0 = 1;
dshot_tx_rmt_item[i].duration1 = dshot_config.ticks_zero_low;
dshot_tx_rmt_item[i].level1 = 0;
}
dshot_tx_rmt_item[i].level0 = 1;
dshot_tx_rmt_item[i].level1 = 0;
}
// ...end marker added to each frame
dshot_tx_rmt_item[DSHOT_PAUSE_BIT].duration0 = DSHOT_PAUSE_BIDIRECTIONAL;
dshot_tx_rmt_item[DSHOT_PAUSE_BIT].duration0 = (dshot_config.ticks_per_bit * DSHOT_PAUSE);
dshot_tx_rmt_item[DSHOT_PAUSE_BIT].level0 = 0;
dshot_tx_rmt_item[DSHOT_PAUSE_BIT].duration1 = 0;
dshot_tx_rmt_item[DSHOT_PAUSE_BIT].level1 = 0;
@ -172,19 +160,15 @@ uint16_t DShotRMT::calc_dshot_chksum(const dshot_packet_t& dshot_packet) {
uint16_t packet = DSHOT_NULL_PACKET;
uint16_t chksum = DSHOT_NULL_PACKET;
if (dshot_config.bidirectional) {
// ...implement bidirectional mode
} else {
// ...same initial 12bit data for bidirectional or "normal" mode
packet = (dshot_packet.throttle_value << 1) | dshot_packet.telemetric_request;
for (int i = 0; i < 3; i++) {
chksum ^= packet; // xor data by nibbles
packet >>= 4;
}
chksum &= 0b0000000000001111;
if (dshot_config.bidirectional) {
// ...calc the checksum "inverted" / bdirectional mode
chksum = (~(packet ^ (packet >> 4) ^ (packet >> 8))) & 0x0F;
} else {
// ...calc the checksum "normal" mode
chksum = (packet ^ (packet >> 4) ^ (packet >> 8)) & 0x0F;
}
return chksum;
@ -192,7 +176,6 @@ uint16_t DShotRMT::calc_dshot_chksum(const dshot_packet_t& dshot_packet) {
uint16_t DShotRMT::prepare_rmt_data(const dshot_packet_t& dshot_packet) {
uint16_t prepared_to_encode = DSHOT_NULL_PACKET;
uint16_t chksum = calc_dshot_chksum(dshot_packet);
prepared_to_encode = (dshot_packet.throttle_value << 1) | dshot_packet.telemetric_request;

10
src/DShotRMT.h
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@ -9,12 +9,10 @@
#include <Arduino.h>
#include "BlheliCmdMap.h"
// ...utilizing the IR Module library for generating the DShot signal
#include <driver/rmt.h>
#include <string>
constexpr auto MOTOR_NUM_PHASES = 3;
constexpr auto MOTOR_NUM_COMMUTATION_STEPS = 6;
constexpr auto DSHOT_CLK_DIVIDER = 8; // ...slow down RMT clock to 10 ticks => 1ns
constexpr auto DSHOT_CLK_DIVIDER = 8; // ...slow down RMT clock to 0.1 microseconds / 100 nanoseconds per cycle
constexpr auto DSHOT_PACKET_LENGTH = 17; // ...last pack is the pause
constexpr auto DSHOT_THROTTLE_MIN = 48;
@ -22,10 +20,9 @@ constexpr auto DSHOT_THROTTLE_MAX = 2047;
constexpr auto DSHOT_NULL_PACKET = 0b0000000000000000;
constexpr auto DSHOT_PAUSE = 21; // ...21bit is recommended, but to be sure
constexpr auto DSHOT_PAUSE_BIDIRECTIONAL = DSHOT_PAUSE;
constexpr auto DSHOT_PAUSE_BIT = 16;
constexpr auto F_CPU_RMT = 80000000L;
constexpr auto F_CPU_RMT = APB_CLK_FREQ;
constexpr auto RMT_CYCLES_PER_SEC = (F_CPU_RMT / DSHOT_CLK_DIVIDER);
constexpr auto RMT_CYCLES_PER_ESP_CYCLE = (F_CPU / RMT_CYCLES_PER_SEC);
@ -53,6 +50,7 @@ typedef enum telemetric_request_e {
ENABLE_TELEMETRIC,
} telemetric_request_t;
// ...set bitcount for DShot packet structure
typedef struct dshot_packet_s {
uint16_t throttle_value : 11;
telemetric_request_t telemetric_request : 1;