Discussion between tlfong01 and kyrpav

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3:14 AM

@kyrpav I got most of the prototyping boards from TaoBao, some blue, some green, some are 5 hole joint, some 3 joint. I guess you can also find them in AliEx. References below:

TaoBao ***洞洞板***，***實驗板*** (Hole Hole Board, Prototyping Board)

https://dzyj.world.taobao.com/category-746222578.htm?spm=a312a.7700824.w4002-14787471864.31.6df4191fkEJg2s&_ksTS=1644980972782_733&callback=jsonp734&input_charset=gbk&mid=w-14787471864-0&wid=14787471864&path=%2Fcategory-746222578.htm&search=y&parentCatId=13313739&parentCatName=%CA%B5%D1%E9%B0%E5%A3%AC%C3%E6%B0%FC%B0%E5%A3%AC%B8%D0%B9%E2%B0%E5%A3%AC%B8%B4%CD%AD%B0%E5&catName=%B6%B4%B6%B4%B0%E5%A3%AC%CA%B5%D1%E9%B0%E5&catId=746222578&pageNo=1#anchor

tlfong01

3:25 AM

I usually 5 joint boards like (1) below:

(1) 5连孔单面喷锡板2.54/5.08MM间距 10*15CM万能板实验板全玻纤蓝油 - ¥3.80
https://item.taobao.com/item.htm?spm=a230r.1.14.151.437a2b99Lq3Vm4&id=646585854398&ns=1&abbucket=14#detail

(2) PCB电路板双面喷锡绿油玻纤FR4实验板万能板 2*8 3*7 4*6 5*7 9*15
https://item.taobao.com/item.htm?id=567780499776&ali_refid=a3_430620_1006:1104988017:N:Lnc0WvnlH9l%2F%2BKQdIfnP%2BQ%3D%3D:b129c9439970c826de7b3897fa5a3ec2&ali_trackid=1_b129c9439970c826de7b3897fa5a3ec2&spm=a230r.1.14.8#detail

(3) below is also my favourite:

(3) 2连孔单面喷锡板2.54MM间距 7*9CM万能板实验板全玻纤蓝油 ¥1.90
https://item.taobao.com/item.htm?spm=a312a.7700824.w4002-21223910208.11.111044ecrVTvSy&id=646936111885

2 hours later…

tlfong01

5:44 AM

@kyrpav Ah, yes, the tmc2208/2209/2225 uart pins are confusing. You may like to skim my answer to the RpiSE forum's 2208 question to get a rough idea of the tmc's strange uart interface:

Rpi Pico MicroPythpn Controlling TMC2208 / TMC2209 / TMC2225 Stepper Motor Driver Problem - 2021dec27 Viewed 533 times
https://raspberrypi.stackexchange.com/questions/135191/rpi-pico-micropythpn-controlling-tmc2208-tmc2209-stepper-motor-driver-problem

3 hours later…

tlfong01

9:00 AM

Now I have setup the second tmc2225 for basic testing, using XY-LPWM sig gen as step pulse input, and both tmc2225 in standalone mode, no uart control.

The motor spec says min pulse rate is 1k7 pps. But I found that if I set micro stepping to 1/4 resolution, I can lower the freq to as low as 20pps, both motor still move slowly. The max pps is around 4kHz, which the motor starts trembling violently, and not moving at all.

So the operating range is about 20 pps to 3k pps.

Next is to test the Vref, Diag pins, internal current sense resistance, and finally uart config and control.

tmc2225 test 2022feb1601

►

tlfong01

9:31 AM

@kyrpav What do you mean by "distantiators"? Do you mean the DuPont pinstripes and connectors?

tlfong01

9:47 AM

These breadboard jumpers or connectors:

(1) https://item.taobao.com/item.htm?spm=a312a.7700824.w4002-14787471864.21.61387c50WJjP9m&id=571492461591

(2) https://dzyj.world.taobao.com/category-46309243.htm?spm=a312a.7700824.w4010-14787471861.142.597e191f6QY8C9&search=y&parentCatId=46309225&parentCatName=%C5%C5%D5%EB%2F%D7%F9+USB%D7%F9%D7%D3+%C0%E4%D1%B9%CD%B7+%BD%D3%CF%DF%D6%F9&catName=%C5%C5%D5%EB%2F%D7%F9#bd

You can usually get these cheapy TaoBao stuff from AliEx, but not vice versa. :)

tlfong01

10:23 AM

Now I am measuring the tmc2225 Vref and Diag pins' output voltages:

tmc2225 Datasheet Section 2.2 Signal Descriptions TMC2225
VREF 12 AI Analog reference voltage for current scaling or reference current for
use of internal [current] sense resistors (optional mode)
DIAG 18 DO Diagnostic output. Hi level upon driver error. Reset by ENN=high.

I found Vref == 08.2V (It should be factory setting, and I could not find an appropriate Philips screw driver to adjust the trim pot.

I found Diag pin's voltage 0V, which means "no error".

2 hours later…

tlfong01

12:09 PM

Now I am using xy-lpwm to input 2kHz step pulses to the motor controller, and display the motor encoder pulse output waveform.

Now I always dodgy calculations. :)

Calculation
1. XY-LPWM sig gen frequency = 2 kHz = 2000 step pulses per second
2. Stepper Motor = 20 encoder pulses/revolution
3. Stepper Motor Speed = (2000 step pulses/sec) / (20 encoder pulses/revolution) = 100 rps