Portenta H7: ADC Implementation #76
Description
In order to get ADC working on the H7 used the Giga Overlay as the model. The following changes were made to the arduino_portenta_h7_m7.overlay:
&adc1 { pinctrl-0 = <&adc1_inp12_pc2 &adc1_inp13_pc3 &adc1_inp18_pa4 &adc1_inp3_pa6 &adc1_inp0_pa0_c &adc1_inp1_pa1_c>; pinctrl-names = "default"; st,adc-clock-source = <SYNC>; st,adc-prescaler = <4>; status = "okay"; #address-cells = <1>; #size-cells = <0>; channel@c { reg = <12>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = <ADC_ACQ_TIME_MAX>; zephyr,resolution = <16>; }; channel@d { reg = <13>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = <ADC_ACQ_TIME_MAX>; zephyr,resolution = <16>; }; channel@12 { reg = <18>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = <ADC_ACQ_TIME_MAX>; zephyr,resolution = <16>; }; channel@3 { reg = <3>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = <ADC_ACQ_TIME_MAX>; zephyr,resolution = <16>; }; /* PA0_C and PA1_C */ channel@0 { reg = <0>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = <ADC_ACQ_TIME_MAX>; zephyr,resolution = <16>; }; channel@1 { reg = <1>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = <ADC_ACQ_TIME_MAX>; zephyr,resolution = <16>; }; }; &adc3 { pinctrl-0 = <&adc3_inp0_pc2_c &adc3_inp1_pc3_c>; pinctrl-names = "default"; st,adc-clock-source = <SYNC>; st,adc-prescaler = <4>; status = "okay"; #address-cells = <1>; #size-cells = <0>; channel@0 { reg = <0>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = <ADC_ACQ_TIME_MAX>; zephyr,resolution = <16>; }; channel@1 { reg = <1>; zephyr,gain = "ADC_GAIN_1"; zephyr,reference = "ADC_REF_INTERNAL"; zephyr,acquisition-time = <ADC_ACQ_TIME_MAX>; zephyr,resolution = <16>; }; }; ..... adc-pin-gpios = <&gpioz 0 0>, /* analog only */ <&gpioz 1 0>, /* analog only */ <&gpioz 2 0>, /* analog only */ <&gpioz 3 0>, /* analog only */ <&gpioc 2 0>, <&gpioc 3 0>, <&gpioa 4 0>, <&gpioa 6 0>; ... io-channels = <&adc1 0>, <&adc1 1>, <&adc3 0>, <&adc3 1>, <&adc1 12>, <&adc1 13>, <&adc1 18>, <&adc1 3>; }; In the conf file enabled CONFIG_ADC=y
Also added the pure_analog_pins,h and ,cpp files modified to use the H7 Analog Pins A0-A3.
Rung out the analog pins a0-a7 using a analog joystick from adafruit:
void setup() { // put your setup code here, to run once: pinMode(LED_BUILTIN, OUTPUT); //pinMode(10, OUTPUT); // PC2 Serial.begin(115200); while (!Serial && millis() < 4000) {} } void loop() { digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN)); //digitalWrite(10, !digitalRead(10)); Serial.print(analogRead(A0)); Serial.print("\t"); Serial.print(analogRead(A1)); Serial.print("\t"); Serial.print(analogRead(A2)); Serial.print("\t"); Serial.print(analogRead(A3)); Serial.print("\t"); Serial.print(analogRead(A4)); Serial.print("\t"); Serial.print(analogRead(A5)); Serial.print("\t"); Serial.print(analogRead(A6)); Serial.print("\t"); Serial.print(analogRead(A7)); Serial.println(); delay(250); if (Serial.available() ) { while (Serial.read() != -1) {} //analogRead(A4); } } While A0-A3 and A6/A7 worked as expected found A4 and A5 were non operational. We tried a few things but no luck.
@KurtE instrumented a simple test sketch to print out the pin configs
void print_gpio_regs(const char *name, GPIO_TypeDef *port) { //printk("GPIO%s(%p) %08X %08X %08x\n", name, port, port->MODER, port->AFR[0], port->AFR[1]); Serial.print("GPIO"); Serial.print(name); Serial.print(" "); Serial.print(port->MODER, HEX); Serial.print(" "); Serial.print(port->AFR[0], HEX); Serial.print(" "); Serial.println(port->AFR[1], HEX); } void show_all_gpio_regs() { print_gpio_regs("A", (GPIO_TypeDef *)GPIOA_BASE); print_gpio_regs("B", (GPIO_TypeDef *)GPIOB_BASE); print_gpio_regs("C", (GPIO_TypeDef *)GPIOC_BASE); print_gpio_regs("D", (GPIO_TypeDef *)GPIOD_BASE); print_gpio_regs("E", (GPIO_TypeDef *)GPIOE_BASE); print_gpio_regs("F", (GPIO_TypeDef *)GPIOF_BASE); print_gpio_regs("G", (GPIO_TypeDef *)GPIOG_BASE); print_gpio_regs("H", (GPIO_TypeDef *)GPIOH_BASE); print_gpio_regs("I", (GPIO_TypeDef *)GPIOI_BASE); print_gpio_regs("J", (GPIO_TypeDef *)GPIOJ_BASE); print_gpio_regs("K", (GPIO_TypeDef *)GPIOK_BASE); } void setup() { // put your setup code here, to run once: pinMode(LED_BUILTIN, OUTPUT); //pinMode(10, OUTPUT); // PC2 Serial.begin(115200); while (!Serial && millis() < 4000) {} show_all_gpio_regs(); } void loop() { digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN)); //digitalWrite(10, !digitalRead(10)); Serial.print(analogRead(A0)); Serial.print("\t"); Serial.print(analogRead(A1)); Serial.print("\t"); Serial.print(analogRead(A2)); Serial.print("\t"); Serial.print(analogRead(A3)); Serial.print("\t"); Serial.print(analogRead(A4)); Serial.print("\t"); Serial.print(analogRead(A5)); Serial.print("\t"); Serial.print(analogRead(A6)); Serial.print("\t"); Serial.print(analogRead(A7)); Serial.println(); delay(250); if (Serial.available()) { show_all_gpio_regs(); while (Serial.read() != -1) {} Serial.println("Paused"); while (Serial.read() == -1) {} while (Serial.read() != -1) {} //analogRead(A4); } } and found that pins A4 and A5 modes were set to AF5 which according to the spec
identifed a4 and a5 as MISO and MOSI for SPI2.
@KurtE found there was an open issue [RFC] Add device init/de-init functionality in Zephyr related to this.
So besides some PWM pins being non-operational we now have some analog pins non-operational.