LCS-1M - A Low-Cost Hobby Oscilloscope
 | |  | |  | |  | |  | |  | |  |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
This page shows how to upgrade your existing LCS-1M oscilloscope from the original Picaxe 28X1 with
MAX232 interface to the new Picaxe 28X2 with the simple resistor interface. In order to use the
upgraded scope you also need to burn the new firmware into the microcontroller, and install the new
PC software.
The hardware changes are somewhat different for the three versions of the scope that are currently out
there (see the "Design Files" page for a short overview of the three designs). The good news is, all
three versions can be upgraded and will show the same performance after the upgrade. Note that
while the PC software is the same for all three versions, you need to make sure that you burn the
correct version of the firmware into the microcontroller (depending on your scope version). If you
accidentally choose the wrong version you won't damage anything, but the scope will not work correctly.
So after this introduction, here we go. Look at the silkscreen label on the board if you are unsure which
version you have:
MAX232 interface to the new Picaxe 28X2 with the simple resistor interface. In order to use the
upgraded scope you also need to burn the new firmware into the microcontroller, and install the new
PC software.
The hardware changes are somewhat different for the three versions of the scope that are currently out
there (see the "Design Files" page for a short overview of the three designs). The good news is, all
three versions can be upgraded and will show the same performance after the upgrade. Note that
while the PC software is the same for all three versions, you need to make sure that you burn the
correct version of the firmware into the microcontroller (depending on your scope version). If you
accidentally choose the wrong version you won't damage anything, but the scope will not work correctly.
So after this introduction, here we go. Look at the silkscreen label on the board if you are unsure which
version you have:
- All versions (V1.0, V1.1, and V1.3):
- Carefully remove the Picaxe 28X1 from its socket and replace it with the Picaxe 28X2.
- Unsolder and replace the 16 MHz resonator with a standard 3-pin 10 MHz resonator.
- Scope version V1.0 only:
- On the bottom of the printed circuit board add a jumper wire between legs 6 (Serial TX)
and 18 (In7/OutC7) of the Picaxe 28X2.
- (Optional) Connect the power LED to Out4 (accessible on the expansion connector)
instead of the power rail.
- Download the new firmware (don't forget to move the jumper to "DL" and then back to
"TX"!).
- Scope version V1.1 only:
- Carefully remove the MAX232 from its socket (if it is installed)..
- In the empty MAX232 socket, connect legs 8 and 9 with a 22 kOhm resistor (or solder it
onto the bottom side of the PCB, but putting it into the socket is more easily reversible).
- In the empty MAX232 socket, connect legs 7 and 10 with a 180 Ohm resistor (exact value
not critical, anything between 100 Ohms and 500 Ohms should work).
- Download the new firmware (don't forget to move the jumper to "DL" and then back to
"TX"!). The Power LED should blink 3 times after download and after each powerup.
- Scope version V1.3 only:
- Carefully remove the MAX232 from its socket (if it is installed)..
- In the empty MAX232 socket, connect legs 8 and 9 with a 22 kOhm resistor (or solder it
onto the bottom side of the PCB, but putting it into the socket is more easily reversible).
- Install R26 (if not already installed) - a 180 Ohm resistor (exact value not critical,
anything between 100 Ohms and 500 Ohms should work).
- Download the new firmware (don't forget to move the jumper to "DL" and then back to
"TX"!). The Power LED should blink 3 times after download and after each powerup.