Build Instructions
I’m a electronics hobbyist. Everything is self-taught. I have created this primarily for my own use and provide the material as is. Use at your own risk. If you burn your house or damage your devices, I cannot be held responsible no matter whether it is your fault when assembling or my fault due to the design. I can only provide very limited assistance through github. You have been warned. If in doubt, please go to someone or buy from someone who knows what he is doing, is insured for damages he causes and possibly provides warranty on the cards. Make sure you read and understand the license.
This version of the opensrxcard is ready to be used. I suggest to purchase the board preassembled SMD components from JLCPCB. I will describe the procedure below as you’ll have to preorder parts in your personal parts bin and it's likely that not everyone is familiar with the process. You’ll still have to hand solder two through hole parts.
Two parts need to be hand soldered on each opensrxcard. As most people are familiar with Mouser, I’ll list part numbers of Mouser here. If you want to order somewhere else, you’ll find the necessary details on the Mouser page. The quantity refers to the number of components needed for a single opensrxcard. You’ll need to order these separately, they won’t be delivered by JLCPCB.
| Quantity | Description | Manufacturer No. | Mouser No. | Comment |
| 1 | JAE Connector | TX24-80R-6ST-H1E | 656-TX24-80R-6ST-H1E |
This is the connector that plugs onto the Roland mainboard. |
| 1 | 2.54mm 2x2 pin socket (2 rows, 4 positions) | 5-534206-2 | 571-5-534206-2 |
Just an example. You can use any 2.56 pin sockets. |
When soldering the JAE connector to the card, make absolutely sure that you are soldering it in the right orientation. The red markers in the next image show where the markers on the JAE connectors are.
The SMD part numbers are embeeded in the kicad file to generate the assembly files for JLCPCB. In the schematic, these are the LCSC attributes. You can check the properties of these components on https://www.lcsc.com/.
This card is not ready yet.
There is no preassembly files for the SRX programmer shield as there is only one SMD component on it which is reasonably easy to solder. So this PCB must be hand assembled.
| Quantity | Description | Manufacturer No. | Mouser No. | PCB component | Comment |
| 1 | Arduino Due | A000062 | 782-A000062 | Make sure you order with pin headers, there are versions without pin headers. | |
| 1 | JAE Connector | TX25-80P-6ST-H1E | 656-TX2580P6STH1E |
J8 | This is where the opensrx plugs on to. Make sure the orientation is correct! |
| 1 | 2.54mm 2x2 pin header (2 rows, 4 positions) | 826656-2 | 571-826656-2 | J9 | |
| 1 | 10uF tantalum capacitor 20V, 3216 package | T494A106M020AT |
80-T494A106M020
|
C1 | This exact component is untested. Make sure you solder this in the right orientation. Polarity is critical. Wrong orientation may cause fire! |
| 5 | 2.56mm pin header, male, 8 positions, 1 row | 68001-208HLF | 649-68001-208HLF | J1, J3, J5, J6, J4 | Untested! These should point down to the Arduino Due. |
| 1 | 2.56mm pin header, male, 10 positions | 68001-210HLF | 649-68001-210HLF | J2 | Untested! These should point down to the Arduino Due. |
| 1 | 2.56 pi, header, male, 2 rows, 36 positions | 77313-118-36LF | 649-77313-118-36LF | J7 | Untested! These should point down to the Arduino Due. |
| SW1, SW2, SW3 | Leave unassembled. |
When soldering the JAE connector, make sure you solder it in the right orientation. In the next image, the markers denote where the JAE connector on the srx programmer has notches (or cut-outs) for the JAE connector on the opensrxcard. The JAE connector on the card has bulges that need to fit the notches.
A small disclaimer beforehand: once I have written this, I will not regularly order these cards. As a result, I won't know when parts are becoming unavailable unless I am told. There is a chance that if you proceed without double checking and checking for part completeness, that you might end up in a situation for a part might not be available any more or cannot be procured by JLCPCB. This might be unfortunate if you have already paid for a few parts and others cannot be delivered. Most parts except for the flash nor ICs can be replaced easily. Replacing the flash nor ICs is more challenging as it might require a different firmware. Just be aware of these things. Going ahead with the guide now.
Ordering an opensrxcard from JLCPCB is a process that may need a few weeks as the board requires components that are usually not available by default at JLCPCB. We'll go through this by example with the opensrxcard 3.3V.
To preorder the necessary parts, you’ll have to work with parts manager.
There, you should use the BOM tool to preorder the necesssary parts.
In the github repository, you’ll find the assembly files in the directory kicad/srx-card-3.3v/production. The files are called bom.csv and positions.csv. The srx-card.zip is the gerber file. For the BOM tool, you’ll drag the bom.csv into the upload panel. After that, you’ll select the quantity of boards you want to order. To my knowledge, the minimum number of boards you can order preassembled is 5. After that, the BOM tool will match the parts with their quantity with their internal database. You’ll be presented the following screen:
The most critical parts are the flash nor ICs (MT28EW128ABA). They are critical as in my attempts, JLCPCB wasn't able to procure them directly.
In this case in the screenshot above, JLCPCB suggests that they need to be preordered. What that means is that you’ll pay full or give an advance on the prices, but you’ll receive a quote for the component afterwards after JLCPCB has checked how they can obtain the part for you. This price can be higher or lower than the price indicated here! They will buy the part for you if the price is lower or equal. If the price is lower, they will give you a refund for the difference. If the price is higher, they give you a choice whether you want to order and ask you to pay for the difference on the JLCPCB website to proceed. In my case, I have received a „quotation failed“ e-mail for the MT28EW128 ICs. Any in case, you’ll receive an e-mail for each preordered part with a success or failure note. There is not guarantee in either direction.
In our case, we decide to buy the parts through the global sourcing in the parts manager as we assume that JLCPCB will fail to supply the ICs and will charge a higher price for it. Global sourcing means, they’ll order the parts from a big supplier like Mouser for you. In any case, you’ll have to choose whether you want to try JLCPCB to obtain the MT28EW128 for you or whether you want to remove this item from the JLCPCB Parts order process right away. In the worst case, you’ll lose 2 days until you get a refund if you choose to let JLCPCB try to get it. Be sure though to order the remaining parts as otherwise, it’s pretty likely they won’t have enough in stock when you are the assembled PCBs!
So, let’s assume you decide to order the flash nor ICs through global sourcing. This is how it works. In the parts manager, go to „global sourcing parts“.
For the flash nor ICs, enter MT28EW128ABA1LJS-0SIT into the „MFR Part #“.
You’ll now receive a list of suppliers you can choose from:
You’ll need flash nor ICs per opensrxcard. So make sure you add the right amount. Click on this „Add“ button. The next step is a little weird as the order cart on the top right doesn’t change. This is because the global sourcing cart is a different one from the upper right cart. You need to click the Parts Cart on the left first and then the Global Sourcing Parts on the top.
As you can see, the Mouser price is lower than the JLCPCB price that they indicated in the pre-order parts. So it probably makes sense to order these through global sourcing right away.
Once you have ordered the JLCPCB parts and the global sourcing parts, you’ll wait for emails from JLCPCB to arrive that they have arrived.
Once all parts have arrived in you parts bin, you can order the preassembled PCBs. If you don’t want to keep track of you emails, you can inspect the status of your orders in the Parts Manager → Parts Order History menu item.
If all party are in status „Complete“, we can order the preassembled PCBs.
Click on „Order now“. Make sure you do that in a Chrome based browser, Firefox has problems with the component placement preview!
Drag the ZIP file from the kicad/srx-card-3.3v/production directory on to the „Add Gerber file“ upload area. After that, you’ll get a preview of the PCBs at the top. Usually, you can leave the parameters as is, you should check the PCB quantity parameter whether it matches your target quantity and you may want to customize the color.
Next, enable the PCB assembly slide button. Make sure the quantity matches and I recommend to enable the confirm parts placement option. You’ll see in a moment why. Other than that, you can hover over the ? Tooltips to see whether you want to enable other options. I usually leave them as is.
Agree to the conditions of the assembly service and click on „Confirm“.
In the first step, you’ll be presented a graphical PCB representation. Click on „NEXT“.
In the next screen, you’ll be asked to upload two files. Grab these from the github repository:
BOM File: kicad/srx-card-3.3v/productrion/bom.csv
CPL File: kicad/srx-card-3.3v/productrion/positions.csv
Click „Process BOM & CPL“. In the next screen, you’ll be presented a screen which parts are used for the assembly. If you have preordered all the parts, they should be available from „Source: My Parts“. As I didn’t preorder any parts before writing this tutorial, You’ll see that JLCPCB grabs a few from JLCPCB directly which seem to be in stock and the flash nor ICs are not available. This shouldn’t be the case if you have preordered.
In the next step, you’ll be presented a preview of the parts placement. For some parts, there may not be graphical models available (e.g. C7 or C3). This is fine. In this example, the flash nor ICs are missing as for writing this guide, I didn’t preorder them.
After that, you are asked to confirm the quote with „Save to Cart“. For customs, you are asked to provide a product description. I choose Research/Education/DIY/Entertainment/DIY – HS Code 902300. You may also choose something like „Development Board“.
Lastly, in the Checkout, make sure you select the highest assembly coupon. These are usually called „SMT Special Offer“. So far, I always had these show up.
After a few hours or at most one or two days, you'll likely receive an e-mail that you should confirm the parts placement. For some reason, the components appear misplaced in the JLCPCB system. This is a know problem and happens in other Kicad based projects as well. The JLCPCB engineers will correct this for you and you can and must confirm the corrected placement in the JLCPCB order history where the DFM analysis is.
If the corrected parts placement looks corrected, you can click on "Yes, please proceed to production".
After that, the production should go through smoothly and you should receive your preassembled boards.