SchematicsAntbot

Antbot Schematics

Overview/Download This is the Unified Board Design that powers both the Antbot and Renegade chassei. It uses one, two or four L298 motor controllers, a Parallax Propeller CPU, and a Bluetooth module (optional).

It is available complete, as a kit (you solder in the motors and the few through-hole components) or as a naked board.

Note the pads under most SMD components: if any of most SMD parts need to be replaced, it should be possible to slide in the equivalent through-hole part and repair the unit with a cheap handheld soldering iron. We would rather make it easy for you to repair our products than sell you another one!

A few components such as the motor controllers are replicated for redundancy.

This is the full layout and schematics of the board: you can download the layout in Scalable Vector Graphics or DXF(zipped) format, and you can download the schematic in PDF format. If you bought the bare board or want to wire the whole thing up yourself, here's a handy bill of materials with Digikey links (CSV format, so you may want to save it rather than viewing it in a browser).

Wiring Explanation The Antbot Board has a few jumper settings that you should be aware of before powering the board up, if you're assembling it from a kit or bare board. In addition, you will find that if you connect all the motors in the same way, they will move in the right direction with the stock firmware.

First and foremost is the battery selector: when using the same battery for electronics, servos and motors (as is the case on the Antbot chassis) you must jump the two "Single battery" pins together. When you're using a larger battery for the motors (as is the case on the Renegade), you should connect it to the MOTPWR + and - terminals and leave the Single Battery terminal unconnected. You can also use a single, high-voltage battery for everything by soldering the appropriate part across all three pins, or use a daughterboard for the same effect. The "single battery" terminal assumes 6 to 10 volts, although it can go as high as 12 if the servo load is not continuous.

The next jumper you should consider is the brownout detection for the Propeller chip -- you may connect the brownout pin to either ground or VDD. If you connect it to VDD, remember to solder a resistor (1k to 10k values are acceptable) between the reset pin and VDD using the pin next to it -- the jumper pins have been positioned so that you may use the leftover resistor wire as a jumper before cutting it. Note that most Parallax Propeller boards just wire the brownout detection low, but that is a matter of preference. From the Parallax website: BOEn: Brown Out Enable (active low). Must be connected to either Vdd or Vss. If low, RESn becomes a weak output (~5 KO) for monitoring purposes but can be driven low to cause reset. If high, RESn is a CMOS input with Schmitt Trigger.

Finally, there are two pairs of jumpers near the Bluetooth module. In order to allow for multiple brands of Bluetooth modules while not giving up connector pins on the Propeller, these jumpers must be set according to the pinout for the Bluetooth module: for example, the RN-42 wants the upper jumpers while the CuteDigi or Sure Electronics module wants the lower jumpers. This is because while bluetooth UART modules have a more or less standardized form factor, pinouts vary.

Please note that if you're buying a complete board, these jumpers will be preset for you according to your specification.

Finally, the power connector on the Antbot takes an audio plug by default: there are extra leads to accommodate other types of plugs (coaxial, adaptaplug, etc.). The Renegade chassis uses a panel-mount style charging plug since there are fewer space constraints.

Page last modified on April 15, 2014, at 12:23 AM
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