X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient: geda-user AT delorie DOT com
X-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=m0n5t3r.info; s=m0n5t3r;
        h=subject:to:references:from:message-id:date:user-agent:mime-version
         :in-reply-to:content-type:content-transfer-encoding;
        bh=Sv7WgeBorR876l6/ti7xj2Ua4/mHD5ZLoRvAdlzyPag=;
        b=GRRg6KzQLAarlMLBVaw7UwJZmkgEWzgYIt7ZXs5dQ/U+4bux9C8VvZd9g6EHqj07RD
         edbEWvFF/4khCrh6Ixzt1EfwHDuT2RSV7WqFYA16zw1cImscs37Qun4nCjaYOmcOCUEJ
         uaph0ej+4lZGvjf0cD7qAEKAodJ6mI3f9Bfrg=
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20130820;
        h=x-gm-message-state:subject:to:references:from:message-id:date
         :user-agent:mime-version:in-reply-to:content-type
         :content-transfer-encoding;
        bh=Sv7WgeBorR876l6/ti7xj2Ua4/mHD5ZLoRvAdlzyPag=;
        b=ETCmpq/zrX0HRwI/WxDzr7a9vzBSbQGhThMf2irH5ZX871Q4ZB8P7vXWD1y1UpH8Ok
         1af6eUXJRpksxkiIRtSb+UAyRHpcKKFPt+EF9nldWgJarcaN5/7qZ0K3TR22ZBNrlorQ
         Ga2rGQANz7xy3R+X2XAxzvnwXhVOLNnkmn7STs0TeO46hl/pg34iOmduZ6DRiFaNbZZW
         cGKaTK94ZvjInnZiNd8Vhdw63oxzZQQBueodQ5NGEFeJ2VQHbyVvbtpn+8hf3Eh8Ltxr
         IlzWEtlp7tZHRsjEHavAov+OM2YmAH8lytOn2E7hUGMcqzFvvaPrhazXH093AUh5XBu7
         QxVA==
X-Gm-Message-State: ALoCoQmJg3IeD1lorPYxqVXKOHsj0GpJ93qO7Y4zUxKBPmGYqXYK54K6d63OTaoi0koAufO539Dy
X-Received: by 10.180.84.67 with SMTP id w3mr11933124wiy.68.1431499646485;
        Tue, 12 May 2015 23:47:26 -0700 (PDT)
Subject: Re: [geda-user] Stepper driver issues
To: geda-user AT delorie DOT com
references:
 <CALSZ9goH9CUT=5DStdVUG4d45ff30WieHc2-DsXpjX=7cf42Nw AT mail DOT gmail DOT com>
 <5536A38F DOT 50104 AT m0n5t3r DOT info>
 <CALSZ9gpoqcOxNRDvwEHipCgkHq0z+KmPY2AWBdRC_DRnz5SD+w AT mail DOT gmail DOT com>
 <20150422013637 DOT GF29418 AT cicely7 DOT cicely DOT de>
 <CALSZ9go_mem7Kt5GD0_yBx=KP86zzVV0hDiY9K62k41FoTDnig AT mail DOT gmail DOT com>
 <20150422161012 DOT GA42355 AT cicely7 DOT cicely DOT de>
 <CALSZ9grVrYv0BS3_y7ez8VXBwTXxAMazWB6gdCuLUe2+6Uzzyw AT mail DOT gmail DOT com>
 <CALSZ9gq73RBxHV5LPe7pQWNO3kK7EPXaRiN0U7zFBV9BsQX78w AT mail DOT gmail DOT com>
 <55395CD0 DOT 70107 AT m0n5t3r DOT info> <20150423214501 DOT GD47936 AT cicely7 DOT cicely DOT de>
 <CALSZ9gqTUxFHLuwfGKosQ3u=1iJcNc2e26GyfhgByB3QJ7Gkkw AT mail DOT gmail DOT com>
From: "Sabin Iacob (iacobs AT m0n5t3r DOT info)" <geda-user AT delorie DOT com>
x-enigmail-draft-status: N1110
message-id: <5552F37A.3050708@m0n5t3r.info>
Date: Wed, 13 May 2015 09:47:22 +0300
user-agent:
 Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.0
mime-version: 1.0
in-reply-to:
 <CALSZ9gqTUxFHLuwfGKosQ3u=1iJcNc2e26GyfhgByB3QJ7Gkkw AT mail DOT gmail DOT com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Reply-To: geda-user AT delorie DOT com

On 05/12/2015 11:37 PM, Rob Butts (r DOT butts2 AT gmail DOT com) wrote:
> Hi Bernd and anyone else who can offer advice about the
> DRV8825 stepper driver,
>
> Have you used the DVR8825 in an application?

I made a little board for it and used it for a proof of concept; worked
fine, then the project (motorized telescope mount) ended up on the
backburner due to a combination of lack of time and shinier things
showing up

>
> I spun a new test board with the bare minimum circuitry to support
> both a pic16f1937 microchip processor and the DRV8825.  I set up the
> micro io to control the stepper driver to drive a nema 23.  With the
> DRV8825 not plugged in I'm able to toggle the 8 control lines to the
> DRV8825.  When I plug in the DRV8825 the Step and Dir lines are held
> low.  I've used two different DRV8825s from two different
> suppliers with the same outcome.

(assuming the enable and reset and sleep lines have the correct logic
levels - reset and sleep must be high, enable low - I know I got that
wrong by connecting enable and sleep together on my first try)

held low as in "micro says high, line stays low"? is it a breakout board
of some sort? try to measure the resistance between the pins and ground
with the thing off, maybe you got the pinout wrong (according to the
datasheet the internal pulldown resistors should be 100k)

if it's not a breakout board: circuit mistake? bad soldering? I would
guess the likelihood of two faulty chips from separate suppliers is
rather low

>
> The schematic of the DRV8825 shows the two lines as inputs.  The TI
> DRV8825 datasheet shows both as inputs with internal pulldown resistors.
>
> Aside from what I've said is there something I'm missing?  Have you
> found the DRV8825s to be faulty?  Some of the comments on the internet
> elude to faulty.
> ​