TouchDRO Quadrature board is designed to interface standard quadrature scales to TouchDRO Android application. It supports up to four scale inputs, directional tachometer, and touch probe input. All inputs are buffered and 5V-tolerant. Scale inputs can be either single-ended, or differential (for better noise immunity).
Those of you that follow the TouchDRO Users G+ community know that I've been working on a pre-made adapter board for iGaging scales. Today I finished testing the first batch of the boards and will ship them out to the people that ordered them. The intention of this post is to clarify what the board does and doesn't do, as well as provide some basic instructions how to set it up.
I test TouchDRO on a number of devices ranging from 10" Galaxy Note Tab to an old LG phone with 4" screen. One of the reasons being that there are subtle differences between devices, event if the OS version and build are the same and some devices work much better than others. For years I've been recommending Google Nexus 7 or Galaxy Tab 7. I use both devices for development and in the garage and stand behind my recommendation. Unfortunately those tablets aren't cheap. Up until now the alternative was to get a no-name Chinese tablet. While these tablets cost half as much, quality of software and hardware varies wildly. For some time I've been looking for an inexpensive tablet that is readily available and offer consistent and reliable performance and finally I found one that fits the bill: Amazon Fire 7" tablet for $49.99.
For almost a year since the last major release of TouchDRO (v2.0) I've been working on the new features and enhancements that will be released in v2.5. Some of the changes are pretty deep under the hood and will not be immediately obvious, but there is a number of features that will make the application more flexible and more convenient to use. This includes a complete revamp of the low-level readout processing with better metric mode support, new functions, improved graphical mode and several quality-of-life enhancements.
Recently I posted a mini review of the iGaging Absolute DRO Plus scales that covered the some basic information on the connection scheme, etc. As I mentioned in the last post, the scales use a different communication protocol. Unlike the DigiMag scales, these scales require additional circuit between them and the MSP430 LaunchPad board. As promised, in this post I will provide instructions on how to connect the scales to the MSP430 Launchpad controller.
Since their initial release iGaging Absolute DRO Plus scales seem to be gaining momentum. They have a lot going for them, but unfortunately they are incompatible with the original 21-bit iGaging protocol. For some time I've been getting an increasing number of request to add support to the controller firmware, so a few months ago I went ahead and purchased a 6" scale to experiment with. Finally last weekend I added support for these scales to the "Mixed Scales" MSP430 controller firmware. In the first part of this post I will explain what's different about the Absolute DRO+ scales and provide a quick overview of the data protocol; in the second part I'll provide detailed instructions on how to connect them to the MSP430 Launchpad DRO controller.
A few posts ago I offered some general ideas on adding a tachometer to TouchDRO setup that covered some theory and a basic example circuit. Since then I've received a ton of emails asking for more details, so in the next few posts I will provide a detailed start-to-finish example of building a tachometer for my Jet 1024 Lathe. In the post "DIY Tachometer for Your Mill or Lathe" I covered the basic of tachometer operation and provided a basic tachometer circuit using a IR emitter/receiver couple. A number of people wanted to use a Hall effect sensor with a magnetic encoder disk, so I will go that route for this design. Along the way I will use this project as mini-tutorial for some of the basic TouchDRO functionality.