Get actual current micro-step

[djairline]

Hi ! Thank you very much for this library ! It works amazingly well and is really easy to use. I am using the tmc2208 to control my stepper on arduino (no 3D printer here :p). I would like to get the current position between my fullsteps but I can't get driver.cur_a() or driver.MSCNT() to work, when I print the result it always give me zero (even when I am not expecting to be on a fullstep)

Here is my code :

// Author Teemu Mäntykallio, 2017-04-07

// Define pins

define EN_PIN 5 // LOW: Driver enabled. HIGH: Driver disabled

define STEP_PIN 13 // Step on rising edge

define RX_PIN 8 // SoftwareSerial pins

define TX_PIN 9 //

uint16_t nbStep = 0;

include

// Create driver that uses SoftwareSerial for communication TMC2208Stepper driver = TMC2208Stepper(RX_PIN, TX_PIN); bool intpolvar = false; bool dir = true;

void setup() { Serial.begin(250000); while(!Serial); driver.beginSerial(115200); // Push at the start of setting up the driver resets the register to default driver.push(); // Prepare pins pinMode(EN_PIN, OUTPUT); pinMode(STEP_PIN, OUTPUT);

driver.pdn_disable(true); // Use PDN/UART pin for communication driver.I_scale_analog(false); // Use internal voltage reference driver.rms_current(500); // Set driver current = 500mA, 0.5 multiplier for hold current and RSENSE = 0.11. driver.mstep_reg_select(true); driver.microsteps(16); driver.toff(2); // Enable driver in software

driver.intpol(intpolvar); uint32_t drv_status; driver.DRV_STATUS(&drv_status); Serial.print("drv_status="); Serial.println(drv_status, HEX);

switch (driver.test_connection()) { case 1: Serial.println("Connection error: F"); case 2: Serial.println("Connection error: 0"); default: Serial.println("Connection OK"); }

digitalWrite(EN_PIN, LOW); // Enable driver in hardware }

void loop() { uint32_t test; digitalWrite(STEP_PIN, HIGH); delayMicroseconds(1000); driver.MSCNT(&test); digitalWrite(STEP_PIN, LOW); delayMicroseconds(1000); if(nbStep == 155){ nbStep = 0; Serial.println(test); Serial.println(driver.cur_a()); } else{ nbStep++; } }

Thank you very much for your help

Best

[djairline]

My bad the tx was working so i did not check but the rx was not connected well the scheme for connection of uart helped me a lot

[teemuatlut]

Glad to hear you solved it before I could even read the notification email!

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From: djairline notifications@github.com Sent: Thursday, September 3, 2020 1:19:41 PM To: teemuatlut/TMC2208Stepper TMC2208Stepper@noreply.github.com Cc: Subscribed subscribed@noreply.github.com Subject: Re: [teemuatlut/TMC2208Stepper] Get actual current micro-step (#31)

Closed #31https://github.com/teemuatlut/TMC2208Stepper/issues/31.

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[PeterOFre]

Hi djairline, could you please share your connection schematic. I am using an ESP32 together with an TMC2208 module from bigtreetech and can run it fine in pin mode but want to use spreadcycle mode for more speed. So I need to learn how to use the UART mode. Any help is highly appreciated. best regards Peter

[teemuatlut]

https://learn.watterott.com/silentstepstick/configurator/#hardware-connection https://github.com/bigtreetech/BIGTREETECH-TMC2208-V3.0/blob/master/Hardware/TMC2208connect.png https://github.com/bigtreetech/BIGTREETECH-TMC2208-V3.0/blob/master/TMC2208-V3.0%20manual.pdf

You need to connect your serial Transmit line to Receive line with a 1kOhm resistor and the Receive line to PDN_UART pin on the driver.

[PeterOFre]

Thank you very much for that quick answer, Teemuatlut! It is is working and I am very happy about that. There are still open questions like how can I switch between StealthChop and SpreadCycle. In your example it is not possible for the TMC2208. I am currently even do not know what is the actual mode. I will share my sketch when I have a solution for that. thank you again. Peter