Manufacturing the Bioloid I/O module

[pepperm]

Hi

I was wondering if there are any manufacturing people out there that could help with advise around the mass production of the Bioloid I/O module that a couple of us have been working on in this site's forum posts.

We have a circuit design and I can produce a PCB design for it but need help and or advise with the following:

What parameters do I need to keep to with the PCB design, wire thicknesses, hole diameters, track spacing, vias etc?

Where can I go for manufacturing that is cheap and high quality, and understandable?

Should I get the manufacturer to fit components or should I leave that to the user?

If we sell a self assembly kit, would people like the full kit, specific components or just the pcb?

Additionally, could readers reply to give me an idea of how many of these modules (and what types - kit or part or fully assembled) would be wanted. Details of the Bioloid I/O module can be found in the forum posts but the following are brief details:

Module connects to Robotis serial comms line just like the AX-12 servos and AX-S1 sensor module.

Module provides serial pass through.

Module will be around 2x3x0.5cm in size.

Module can be controlled by the Robotis Behaviour Control Program or any code running on the CM-5.

Module is user programmable. Currently developing code supports serial I/O for the likes of Quadravox speech module, I2C for the likes of the ultrasonic echo modules, general I/O for LEDs, relays switches etc and an accelerometer.

Board includes (or provides for, depending on final product) a 2 axis accelerometer.

Regards

Mark Pepper

[JonHylands]

Interesting - I didn't know the module would be that small. 2cm x 3cm implies that you're using surface mount for at least the microcontroller, right? Which package are you using?

I'm sure its in the ZIP file you posted, but I don't have Eagle, so I can't look at it - can you provide a PNG or something of the PCB layout?

- Jon

[didey]

Jon
EAGLE can be found at www.cadsoft.de but the site is in german.

------------------
Dirk ;o)

[JonHylands]

didey,

I know, but I really don't like Eagle, and I'm sure that the dozens of other people on this board who are interested in this board but will never design a PCB themselves would be much happier looking at a bitmap of the PCB design rather than having to download and install an entire new application just so they can see what the board looks like...

- Jon

[didey]

Jon
you are right. Bitmap its much easier.


pepperm

is it possible to put a additional 3.3V power supply for gyro and acceleration sensor on the module ?
I use the IMU 5 degrees modul from Spark Fun and it need 3.3V power supply.

Do you want use SMD components for the manufactured PCB ?

I prefer a full assembled kit without the connector SV4.
So everybody can soldering his owne connections.

And a 10 pin programming connector.

--------
Regards
Dirk ;o)

[JonHylands]

The layout parameters depend entirely on which board printer you end up using. I use Alberta Printed Circuits (because they are in Canada), and they list the rules on their website you have to follow in order to have an acceptable board for them.

Getting the manufacturer (or a third party) to fit components is a pretty big step. Personally, I would advise waiting for the demand to justify it before looking at that.

Self assembly is going to be very difficult for most people if you're really looking to produce a 20x30mm board. Most of the parts are going to have to be surface mount.

Are you planning on putting the buffer/inverter on this board as well, or are you going to do the same trick I'm doing in software?

I would strongly advise to not include any sensors on the board - some people will want several of these boards, and you're wasting space and/or money by doing that. Alternately, provide several versions of the board, where at least one of those has no sensors included.

- Jon

[limor]

I've had several conversations with Clarence from amainobj.com in Singapore, about "mass" producing this board. They have lots of experience in doing PCB and surface-mount jobs done economically and in small quantities.

I'd like to get some feedback before getting into design details such as through-holes or pin-outs / 3.3V regulator or also 5.5V regulator / female Bioloid socket perpendicular or horizontal to the PCB....

First of all the price!!
We think that the target price at RoboSavvy store after work and shipping costs will end up approaching US$30 (15GBP) 22EUR.

Is that acceptable?

Remember you would have to buy some sensors to connect to the board.
Such as Gyro US$34 , Accelerometer : US$32

Would you buy 2 of these modules for your Bioloid?
( so that you can attach sensors at different parts of the body ..)

[JonHylands]

Boards like this should always have through-holes, with default headers supplied (for connections where you are using standard 0.1" molex headers.

If you're running the microcontroller at 3.3 volts, you have to use an 8 MHz crystal/resonator. If you do that, you won't be able to interface to any of the Analog devices single-axis gyros, because they unfortunately all run at 5 volts, and produce a 0.25 - 4.75 volt analog output.

Whether to use straight or right-angle bus headers kind of depends on where you envision people putting these boards on their robot. With the stock Bioloid humanoid, you've got a huge space under the CM-5, about 60mm x 30mm x 30mm. There's also a big space between the shoulder servos.

$30 USD is a great price in my opinion. I will definitely buy a couple, if just to give me options and ideas.

- Jon

[pepperm]

Interesting - I didn't know the module would be that small. 2cm x 3cm implies that you're using surface mount for at least the microcontroller, right? Which package are you using?

I'm sure its in the ZIP file you posted, but I don't have Eagle, so I can't look at it - can you provide a PNG or something of the PCB layout?

- Jon

The experimental board does not include a surface mounted processor but the production one will. My latest test board is based on the baby orangutan board with a daughter board with the extra components. Here is a picture:


I'm in the UK (Staffordshire) by the way so would prefer a PCB manufacturer that is near by if possible.
Mark

[cat007]

Attached is the photo of my companie's PCB prototyping machine, a LPKF Protomat C20 (Cost about USD 16k)

Prototype for this project will be subsidised in full by Robo-savvy & A-main Objectives.

For mass fab, the shipping will be the killer which is a problem to anywhere unless u can get it do locally.

I am open to suggestions on how we can get it done.

[cat007]

The other part that can be integrated could be the acclerometer.

I have no idea how we can integrate it but the ones we do looks like this.

[pepperm]

Hey Cat007, do you have a smaller picture please, maybe about 320x240 as the one you posted is very very big.

Mark

[cat007]

Hey Cat007, do you have a smaller picture please, maybe about 320x240 as the one you posted is very very big.

Mark

Dear Mark, i realised that too. attached the raw file instead of the edited one. Have changed it. Cheers and keep those ideas coming !!

[pepperm]

Are you planning on putting the buffer/inverter on this board as well, or are you going to do the same trick I'm doing in software?
- Jon

Jon

I have been including the buffer but could just use code like you. However, I suspect that Robotis use the buffer to improve line driving and possibly even processor protection. Have you found any problems running without the buffer with lots of servos on the same line? Robotis must use them for a very good reason.

The reason I have gone surface mount is because I was asked to make the board smaller (Limor I think) and have aimed to get something that will fit into a servo sized container. I was pointed to the Baby Orangutan which is the perfect size and pretty cheap at just $30. Hence the daughter board which has connectors, line driver and a socket for the MX2125 accelerometer. It's a pretty simple board but produces a powerful solution. It makes a great test setup.

I could easily produce a large pinned component version. To be honest I am coping easily with surface mounted components at home (some are less than 1mm square too), and I have glasses! I do need a magnifying glass to check the joints though.

Mark

[pepperm]

I've had several conversations with Clarence from amainobj.com in Singapore, about "mass" producing this board. They have lots of experience in doing PCB and surface-mount jobs done economically and in small quantities.

I'd like to get some feedback before getting into design details such as through-holes or pin-outs / 3.3V regulator or also 5.5V regulator / female Bioloid socket perpendicular or horizontal to the PCB....

First of all the price!!
We think that the target price at RoboSavvy store after work and shipping costs will end up approaching US$30 (15GBP) 22EUR.

Remember you would have to buy some sensors to connect to the board.
Such as Gyro US$34 , Accelerometer : US$32

Would you buy 2 of these modules for your Bioloid?
( so that you can attach sensors at different parts of the body ..)

This looks promosing Limor. In answer to your questions:

5V or 3.3V - 5V would be needed to drive conventional servos and gyros with the usual 3 wire connection I think, but I could add a second regulator to take 3.3V of the 5V supply.

The price looks good at $30.

I would buy 2, at least.

We should be able to include an accelerometer chip on board because I think that is a must have with the Bioloid. Maybe just the socket though, but this will be bigger. Not sure how much the chips are in quantity.

Tell me about the difference between Accels and Gyros then and how many axis's are needed?

Mark