Parts list for order

Hi everone,
I follow the blog for quiet some time now, mostly on the Combineforum. It is amazing to see what Brian has done. Many thanks for that.My wife and me run an organic cash crop and sheep farm in SK, Canada along Lake Diefenbaker. At the moment we have two tractors CaseIH with Trimble RTK System. My goal is to build two systems for spring, one for a Deutz that I use for row crop cultivation with a camera guided cultivator, the other for our swather.

Deutz should have hydr. steering ideally, Swather with steering wheel motor. No section control needed yet. Both should be RTK
Base I want to use also for the trimble system (I use modems and “buy” the correction signal now, costs me a lot of money every year.
Now I have a few questions regarding parts, I am going of the parts list

  • in some video Brian mentions the MMA8451 is the accelerometer of choice to use but the parts list mentions the MMA8452Q from Sparkfun. Which one do I choose?

  • would it make sense to build the autosteer on a breadboard (for learning purposes) or should I use PCB, and who would have them in SK or Canada?

  • should I buy the BNO 055 IMU Compass or should I just wait a bit and then implement the two antenna system some of you are talking about. Or would I need for that a different GNSS receiver than the simpleRTK2B

  • How reliable is the long range radio XBee XSC Pro, 900mHz, is that strictly line of sight or better, all my land is in one block and farm buildings (base station) in the middle with max 2 miles distance to the furthest point, but we have lots of hedgerows and some low spots toward the lake which is about a 30 meter drop.

  • with the simpleRTK2B as base can I use that as a base station for my trimble also?

  • what is the chance of being able to use an old WAS that I have from my first GPS system, it was Reichhardt. And how do I test it out?

One thing that I don’t understand is how come that I don’t need a WAS on the swather but I need one on the tractor or do I need one on the swather but where would I mounted?

My plan is to order parts soon and then put it together in the house and once everything works put it in the swather first with the steering motor and my sons old laptop. Once that is working then I would start on the Deutz and try the same thing but with a hyd. valve block. By then I hope I have a bit of experience and know better what I am doing.

Again thanks everyone for the work you are doing it’s so great to see all the collaboration.

Hello Marcus,

I think your order of plans is well chosen. Starting easy, cheap and in the house is how I confirmed for myself too that I could make it work. Then building it onto the tractor is the fun part (maybe also most challenging but OK). I am happy with the steering motors now and maybe someday I will get into hydraulics.

  • I use MMA 8452 (blue rectangle) which works fine. I think either version is good, but would like to see this verified too.
  • I found it doable to start with an arduino with terminal block adapter for just testing the basics in the house. You could bolt everything in a box and hand-wire like most did a year ago but really, PCB is the way to go.
  • Also very eager to test the double antenna system which simpleRTK2B is perfect for. They have an elegant solution with 2B + 2Blite on top. I have a BNO but haven’t used it the last year so maybe it’s worth to wait.
  • no experience with radio
  • User @torriem had a topic in the combine forum on this. It was possible to use as base station for Trimble but needed some specific settings on the messages going to the Trimble I think.
  • If it has 3 pins, try to identify 5V and GND. Maybe you can find the info you need here: Steering angle sensors
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I have extra pcb’s if you want. They are cheap and I got 10 last time i ordered. Using a pcb makes a more stable system in my opinion. PM me if you want or stop by. We live between Outlook And Delisle.
I put a WAS on a swather. wasnt as stable steering as on a tractor but it worked.

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Here’s some back and forth on the MMA from the Telegram group. We really need to keep all those discussions here as they are easier to find. So here they are:
Brian Tee, [10.09.19 17:18]
Re 8451,2 They are all the same. You just have to chose the right address. Right from the setup in AutosteerPCBv2.ino…

// set to 2 if MMA8452 installed GY-45 (1C)
// set to 3 if MMA8452 installed Sparkfun, Adafruit MMA8451 (1D)

Brian Tee, [10.09.19 17:22]
[In reply to Matthew Elias]
Each field saves 1 AB Line in ABLine.txt. The rest are stored are stored globally.

Wolle, [10.09.19 17:28]
[In reply to Brian Tee]
Brian, thank you, the setting is clear, but why didn’t I have to modify the map command? The 8452 has 12 bit the other 14 bit, so the counts per degree roll is different, isn’t it?

Alan Webb, [10.09.19 17:28]
[In reply to Brian Tee]
Ah right. I wondered if the output would be different with the mma8451 being a 14 bit rather than 12bit as in the mma8452.

Brian Tee, [10.09.19 17:30]
I don’t have one, waiting for one to arrive, so you may have to investigate. Makes sense tho it would be different mapping.

Wolle, [10.09.19 17:38]
I will investigate but I must put my hardware together first.

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maybe this will help

Thanks for all the support. I will update as the project progresses.

I am having an issue with my MMA8451 i purchased from adafruit. it has 8 pin locations and the socket on the pcb only has 6 can i make this work or should i order the one listed from Spark Fun so i can just plug in directly into the pcb?

You can use 8451 if you wire it to the board. See here around post 18 PCB version 2

But I don´t know about the 12 /14 bit issue mentioned around post 4 above this.

Has anyone recently ordered parts for PCB with
Digi-Key or Mouser?
I wonder how much all the parts cost?

It’s about 65€ from Digi-key. Only parts to one PCB+Cytron, no spare parts, no PCB price included. Some parts are out of stock at the moment in Digi-Key.

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I have the specified (6 pin) sparkfun one and an adafruit 8451 8 pin. I had already made up a short ribbon connector to allow me to use the 8 pin one, and because of the orientation of my PCB I’ve actually used that one and hot glued the MMA to my enclosure. Works fine. Mine is a 14 bit one. It works very well.

Only 4 connections are needed. Vcc, GND, SDA, SCL.

The Adafruit one works with 3v3 or 5v so I connected it to the 3v3 pin on the PCB MMA header.

A point of some debate but I have also got the BNO055 glued, away from other things, in the top of the enclosure but, I haven’t got any high load switching going on in there. No Cytron on the PCB. Personally I do wonder if that is why some have issues with the BNO. I could have used the brick but that is another wire going to the roof that I didn’t particularly want. I guess it depends on where you can mount the enclosure.

Everything comes out around 200E together with pcb, in digikey there are no sensors and no power supply.

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I found eBay miles cheaper with postage.

Last spring (when this forum was on CombineForum) I ordered one of the earliest versions of the PCB and tried extremely hard to get this to work. Ordered the electronics from digikey and started sodering. I spent a month or so trying to get this to work and was unable to get it going. Is this the same PCB that was released last year? I really want to get this to work and was wondering if this is a newer PCB that maybe resolved the issues I was having last year.

Sorry to post this to the entire conversation. I think permissions blocked me from sending wwfarm a PM.


I have “Brian’s PCB v2” and it works fine. I’m not sure which PCB you have but I think Brian himself is using the older PCB and his system is obviously working fine. Try to find some posts from Brian that show is PCB. Perhaps your issue is not the PCB but the way you use it?

Maybe it would be just a lot easier to order the ready made board from Andreas? Well, not maybe. It’ll cost about the same as you building it and you know it works.

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I don’t have any extra boards left. Unless you really enjoy electronics and soldering then maybe do as Brian suggested and order from Andreas. I have both versions of pcb working so if you need help with that maybe post some pictures and explain what doesnt work? its maybe something simple and someone on the forum would probably know whats wrong.

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I finally got all my parts and the PCB v2 board ,will it be compatible with the version 4 that is coming out or should I wait and see what the new board will be before I start soldering it up?

I’ve been using it with the very first board ever made, and it works perfectly. I am designing a v4 board as well however.

I just PMed Andreas. Thanks for that suggestion. I had no idea he sold them assembled.


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