8.6 KiB
Getting started
Welcome to the ESCAPE board - this guide will describe all the features of the ESCAPE board and show you how to control up to 6 motors and 6 servos very simply.
Board layout
Before we start to assemble your board, we'll take a look at what each section is and what it is for. Place your ESCAPE board on a table in front of you and identify each area.
CPPM / PPM-SUM
This is the connection that allows you connect a Radio Control (RC) receiver so that you can extend the range of control for your robot.
Motors
The ESCAPE board can control 6 independent motors. Each motor has a connection with three pins onto which you will plug the control wire from the motors ESC unit. The centre pin on the Motor connections aren't connected together. This is because the centre wire from an ESC sends 5v and having multiple 5v power supplies connected to each other can be very bad.
Servos
The ESCAPE board has connections for 6 Servos. They default to being powered by the ESCAPE boards power supply, but we can switch them to be powered by the Raspberry Pi by placing a jumper on the POWER pins (assuming the Raspberry Pi is powered via its USB port).
We can also power the Raspberry Pi by placing an ESC control wire on one of the Servo connects and using the 5v sent on its power wire with the POWER jumper in place.
We'll go into more detail on this later, so don't worry about it for now.
Power
The power connection should accept 5v DC - the power you connect here is isolated from your Raspberry Pi and only goes to the servos unless you have the POWER jumper in place.
Expansion area
This area to the right of the board is for adding extra expansion boards to increase the functionality available to you. For more information on adding expansion boards look here
Address selection
The ESCAPE board uses I2C to control the motors. You can have a lot of I2C controlled boards on your Raspberry Pi at the same time, but each must have a unique address.
We have set up the ESCAPE board to use the address 0x61. If you find that this conflicts with another board you want to use, and you can't change the address of that board, then you can use these 5 solder jumpers to change the ESCAPE board address.
How to change the address
Each of the address pins (A0 - A4) can be set to 0 (un-soldered) or 1 (soldered). You set an address pin to 1 by adding solder to each pad of the address pin until the two parts join.
Each address jumper has a binary value - A0 = 1, A1 = 2, A3 = 4, A4 = 8
The starting address for the ESCAPE board is 0x61 - if you look closely at the jumper pads labelled A0 you will see a small connection between them setting this jumper to 1.
If we solder jumper A1 then the address will be 0x61 + 2 = 0x63. Soldering A1 and A2 will give us 0x61 + 2 + 4 = 0x67
Setup your ESCAPE
Now that we know what each part of the board is for, it's time to solder all the connections - it doesn't matter what order you attach the connections to your board, but we've found that the order below is the simplest.
Assemble the parts
IMPORTANT - if you have an expansion board that you want to add to your 640 board, then you should add that first as it will be a lot easier than adding it after soldering connectors to the board.
As we don't know what headers and connectors you selected when you ordered your ESCAPE board - we're going to show you how to connect the most common selection - other connectors and headers should attach in the same way.
Hint - A lump of plasticine or clay is very useful to hold your board level.
Attach the 2 pin Power jumper
The small 2 pin jumper is the first part to put in place. It goes in the two holes labelled POWER.
Place it in the holes but don't solder it in place yet.
Attach the 7 pin motor header and 6 pin servo header
The next parts to slot into place are the 7 x 3 connector for the CPPM and motors and the 6 x 3 connector for the servos. The holes for these parts are aligned so that the connectors should fit tightly and be held in place.
Slot them in place, and then using a piece of paper or card to hold the connectors in place, turn the board over.
Slide the paper away and use a piece of plasticine or clay to keep the board level on your desk if needed.
Solder all the pins in place - if you solder a single pin on each connector initially, then you can check if they are level and aligned correctly.
If they aren't then apply the soldering iron tip to the soldered pin and move the connector until it is level.
Attach the power terminal
Now we need to add the power connector - slot it in place making sure that you have it the right way around (for the screw terminals the holes should be at the front of the board).
Use a piece of paper or card to hold the connector in place and turn the board upside down. Slide the paper out from under the board and use a piece of plasticine to prop the board up level.
Make sure everything is lined up correctly - use extra plasticine to align connectors if needed. Once you are happy, solder each of the pins.
Attach the header
For this example we'll show you how to connect a stackable header, as it's the most complex.
Due to the length of the stackable headers pins, it can sometimes be a hassle to get them through the holes on the board.
We've found that if you slide up the spacer on the stackable header so that it is near the top, you can get the pins into the boards header holes a lot easier and then slide the spacer back down again.
Once you have your header in place, use some plasticine to make sure the board is level and then solder away. You should solder a single pin first, then make sure the header is level - if it isn't then apply the soldering iron to the pin again and move the header until it is correct.
Now that your board is set up, it's time to configure your Raspberry Pi so that you can use it.
Setting up your Pi
Before we can start using the ESCAPE board we need to enable the interfaces that the board uses on your Raspberry Pi.
The ESCAPE board is controlled using the I2C interface. Any expansion boards attached to your ESCAPE board are controlled using the SPI interface.
Enable I2C and SPI in Pixel
If you are using the graphical interface on your Raspberry Pi then click on your main menu icon, move down to Preferences and click on the Raspberry Pi Configuration menu item. Once open click on the Interfaces tab and you should see something like in the image below.
Make sure that the line labelled I2C is set to enabled.
If you have an expansion board then you'll need to enable the SPI interface as well on the line above, so click the Enabled setting next to the SPI label
Once you click Ok you may be promtped to reboot your Raspberry Pi - go ahead and reboot.
Enable I2C and SPI on the command line
If you are only using the command line on your Raspberry Pi then you will need to use the text version of the Raspberry Pi configuration tool to enable the interfaces.
Type the following to bring up the configuration interface:
$ sudo raspi-config
Once the menu is showing, scroll down to the Advanced Options menu and press Enter.
Now we'll need to enable the I2C interface, so move down I2C menu and press Enter. You'll be asked if you want to enabled I2C - select Yes and you will see a confirmation and be returned to the main menu.
Go to the Advanced Options again and do the same for SPI
This time when you are returned to the main menu, move down to the Finish option (pressing the right arrow key twice will get you there) and press enter.
You have now enabled the interfaces you need to use your board.