Summary of $15.00 BASIC Computer using PIC32MX1 microcontroller
This article introduces the $15 BASIC Computer, a microcontroller project using the PIC32MX1 chip pre-loaded with machineBASIC. It details how to assemble the device using a starter kit or individual components, emphasizing the ease of serial terminal connection, immediate register testing, and running programs from the internet or at reset. The guide covers hardware setup, including power supply requirements (3.3V), specific capacitor values, and wiring instructions for the USB serial interface and breadboard.
Parts used in the BASIC Computer:
- PIC32MX1 IC with machineBASIC loaded
- BV500-s1 Starter kit or standalone IC
- Two 0.1uF capacitors
- One 4.7 to 10uF capacitor
- Solderless Bread board
- Hook up wire
- USB to serial link
- Terminal software (BV_Com)
$15.00 BASIC Computer?
Yes is the answer to all of the above questions. I am the author of machineBASIC and I have been waiting 40 years for a chip manufacturer to produce in a DIL package something powerful enough to run a high level language that is easy to use, thank you Microchip. Some old timers may have heard of a language called Forth. Well this is not Forth but BASIC however it is compiled in the same way as Forth and so has all of the speed and modularisation advantages without the drawback of write only code.
What’s Needed
The IC is a PIC32MX1 with machineBASIC (mB) loaded onto it. It is currently only available from www.byvac.com and can be purchased on its own, as a starter kit or as a more comprehensive kit. I will be explaining here how to get the device going with the starter kit, the individual IC is much cheaper than $15, so you will need the following:
*) Starter kit (BV500-s1) or just the IC if you have a USB to serial link
*) 2 x 0.1uF capacitors
*) 1 x 4.7 to 10uF capacitor
*) Solderless Bread board and hook up wire
*) Terminal software from here http://doc.byvac.com/index.php5?title=Downloads (select BV_Com)
All of the above is provided in BV500-k1 but I will assume that you have already got a breadboard of your own.
Step 1: Video Format
Starting
When the IC’s are new the pins are splayed out and so you need to hold them against a flat surface and use a turning action to push them in otherwise they will not mate with the holes in the breadboard.
Connect link wires to the USB serial interface.
This is the type that comes with the starter kit. If you have your own device than it must be able to work with 3.3V. It doesn’t matter if it is a 5V type as the pins that are used on the IC for the serial interface are 5V tolerant. This type however will supply 3v3 from the VCC pin. RX and TX are essential but the connection to DTR is optional and is used to conveniently reset the device using the free BV_COM software. Convenient as you don’t need to lean over to press any buttons.
The other end of the link wires are pins that will push into the breadboard
Hookup
Here is the complete wiring diagram. Note that there are three ground connections and two connections that go to the 3.3V supply. The Vcap shown here at 10uF is essential, the positive end goes to pin 20. A 4.7uF will also work but 10uF is recommended by the manufacturers. The 0.1uF capacitor connected between 3.3V and ground is there to cut down noise. As a general rule 0.1uF capacitors are sprinkled round electronic circuits much like hundreds and thousands are on a cake.
The 0.1uF capacitor that connects DTR to pin 1 is optional. If you do not have a DTR then use the circuit as shown for resetting the controller.
- How do I prevent static damage when handling the IC?
Touch a large metal object first to ensure you are discharged before touching the pins. - What voltage is required to power the IC without causing damage?
The device works from 3.3V; 5V will damage the IC, though serial interface pins are 5V tolerant. - Can I use batteries to power this project?
Yes, two 1.5V dry cells or three 1.2V rechargeable cells are ideal as the IC works down to 2.5V. - What is the recommended value for the Vcap capacitor connected to pin 20?
A 10uF capacitor is recommended by manufacturers, though a 4.7uF will also work. - Is the DTR connection essential for the serial interface?
No, the connection to DTR is optional and is only used to conveniently reset the device. - Can I use telephone or alarm wire for hooking up the circuit?
Yes, telephone, alarm, or CAT5 wire works fine and can provide a neat job. - Does the machineBASIC language run at high speed?
Yes, it is compiled like Forth, offering all the speed advantages without write-only code drawbacks.
