How to Build a DIY TouchDRO Adapter

TouchDRO scale adapters are designed to be inexpensive and easy to build from readily-available off-the-shelf components. The total cost of a do-it-yourself DRO adapter is between $25 and $50, depending on the type of scales you want to use. The build process itself should take no more than a couple of hours.

Scratch-Build vs. Pre-Made Board

A common question people ask is what is the difference between a scratch-build adapter and an equivalent pre-assembled board. The short answer is that there are no functional differences between the two. In other words, they are pin-compatible and run the same firmware. Do-it-yourself firmware is not crippled or limited in any way besides the "non-commercial use" license. Hardware is slightly different between the two, to make scratch-building easier, but it has no impact on features.The main difference is the cost, convenience and potential long-term reliability.

Scratch building an adapter will take a bit of time and effort but in exchange, you will gain a better understanding how your DRO works. Should something go wrong, you will be better equipped to troubleshoot and fix the issue. Additionally, you will have more flexibility with do-it-yourself adapter since pre-made boards don't cover as many scale types.

A pre-made adapter will almost certainly be more expensive but the assembly, programming, testing and troubleshooting will be done for you. Furthermore, a pre-made board will perform slightly better in a noisy environment since the PCB is more compact, well grounded and will not pick up as much noise as the connecting wires or a DIY addapter. Finally, pre-made board will likely outlast a DIY build since it is built in a controller environment to a strict quality standard.

Where to Start

Building a do-it-yourself adapter requires a cursory understanding of how TouchDRO works, some knowledge of electronics, and basic soldering skills. Before starting a build please familiarize yourself with overall TouchDRO system architecture and the building blocks of a TouchDRO adapter. In addition, it's a good idea to install and configure the TouchDRO application before starting since you will need it for testing.

Choosing the Right Adapter

The deciding factor in TouchDRO adapter selection is the type of scales you intend to use with it, so it's important to ensure that the scales are supported and to understand their requirements. If you will be using capacitive scales, refer to the Compatible Capacitive DRO Scales page. On the other hand, if you are planning to use Glass or Magnetic scales, review the Glass and Magnetic Scales page. Once you have a firm grasp of TouchDRO system architecture and your scales' requirements, it's time to start planning the build and ordering the parts.

Common Adapter Configurations

There are many possible adapter combinations that can be built using the basic building blocks. All of them have the base control circuit in common. In other words, the adapters use the same MSP430 microcontroller, 3.3V power supply, and BlueTooth transceiver. Moreover, all versions of the TouchDRO firmware use the same MSP430 pin mappings.

This means that a DIY TouchDRO build will start with the same foundation that can be built following the steps described on the Building TouchDRO Control Circuit page. Incidentally, a pre-made TouchDRO adapter for iGaging and Shahe scales provides the same control circuit in a more convenient package. This means that it can be upgraded to handle different scale types or used as a foundation for a do-it-yourself build.

Once you have a working base control circuit, you will need to add the input stage appropriate for your scales and, if needed, a secondary power supply. Build instructions for the most common adapter configurations are linked below.