Let's Make Robots!


PICAXE 28X1 and the PLAY command

I came across an interesting problem tonight and thought I would share it.

I was working on Ajax, (robot #1) and decided to use the PLAY command in PICAXE BASIC to make him "sing".

It looked really easy to use, preloaded tunes, give it the pin for the piezo speaker and the number of the tune and it should work.

And it did kind of work.  I worked on EVERY output pin but the one I had the piezo speaker connected to.

I had the piezo speaker on output pin 3 and got ...nothing....

PICAXE 28X1, debug command and servo twitch


I came across something interesting, I thought I would mention.  I had my robot plugged into my computer and was working on the IR range sensor.  This meant I was reading the ADC pin and had a DEBUG command in the code to show me the values I was getting back.

While this was going on, one of the robots arm was ...twitching... a bit, like the robot had suddenly developed Parkinson's disease.

While trying to figure out why that was happening I removed the DEBUG command statement and the problem disappeared.

Using 4 Motors?

Hi all, I've made my first robot using a picaxe 28x1 project board. This uses the L293D to drive my 2 motors (connected to a & b). My question is, if I wanted to power 4 motors from a robot, what would I need to do? Is this hardware capable, or should I be looking at something slightly different?

Also, I have a AXE230 PICAXE-08M Module...which says it can be attached to the board and enable the use of additional servos or other output devices, but does not specify motors.

PICAXE 28x1 Syntax Error

I need help, I'm trying to program a sonar with the PICAXE programing editor and tere's this Syntax error that shouldn't be there.

low portc 0
pulsout b.5,5
pause 200
pulsin portc 0, 1, w1
w1 = w1/29

It only complains with the "pulsin" line, the "low" line doen't create any sort of problems. What's wrong here?

Mapping With Picaxe

   For a current project I want to try mapping a room with a picaxe but do not know how to get started.    With this project I want to be able to find my way to certain places in the room and want to be able to know when I got there.  For example I would want to map a room and I would want to be able to set different spots in the room to look for objects.  Then once it found an object in a certain spot it would take it to another predetermend spot.  An example would be if it would find anything next to the foot of my bed pick it up

Lots of strange Sharp IR Noise…?

Hey everyone. So, I just finished my first robot in a few years, my first being 2 1/2 years ago. This one is a lot more complicated in terms of hardware since I made my own boards and all, and have 5 ICs in one circuit. I'm done with programming and everything runs well but there's one ongoing problem with my Sharp IR GP2D120 sensor.

Accuracy of 28 X1 without external resonator?

In my circuit, I have 2 Picaxe 28X1s. The only suitable external ceramic resonator I have is on the 28 pin project board and I don't want to ruin it by accident during desoldering. I am making my own board for each Picaxe, and need to know how accurate the timing of the Picaxes will be only using the internal resonator. Picaxe A is using 2 PWM channels driving motors on a separate power supply handled by an L293D, all other outputs to drive other ICs, will read 1 ADC channel, 2 digital sensors, and 1 digital input.

Help with Hserin/Hserout commands?

I have 2 Picaxe 28x1's that will need to communicate serially with one another while each performing tasks such as PWM, reading ADC, simple outputs. As I understand, the Hserin and Hserout pins/commands allow the Picaxes to recieve serial data in the background, store it somewhere, and read the stored data whenever necessary. I need Picaxe A to do tasks, and then send 2 variables to Picaxe B without interupting B's program flow. B needs to be able to look up the variable sent from A whenever necessary and continue on. How would I connect the 2 Hserin/Hserout pairs on each Picaxe?

28X1 Pin 7 (Serial Out) Used as Normal Output??

Is it possible to use pin 7 of the Picaxe 28x1, which is normally used in the download circuit, alternately as a normal output that could in my case drive a single LED? If so, what would be the code for it?

Picaxe Serial Communication Through Prog. Socket??

Hey, I'm wondering: If I have 2 Picaxe 28X1's that both have their own programming sockets, after programming them, can I use a male to male audio cable and connect their sockets, and send information from one to the other with serout commands? One 28x1 sends info to the other, no data is sent back, so only on serial line is needed. Is it possible, and how would I implement it?

Speed control with continuous rotation servo?

Hi everyone, I have a quick question regarding servos.

Read GP2D02 into digital input on Picaxe 28x1

I just had a read through of your article "How to make your first robot" on LetsMakeRobots.com. This is a fantastic article, however, I've got one slight problem; I am working with a Sharp GP2D02 instead of GP2D12 and the code needed is somewhat different.

Connecting and programming an SRF005 to starter robot with 28x1?


I am wanting to connect an SRF005 to a 28x1. I am basically building a "start here" robot with all of the same parts as the solarbotics kit apart from the range sensor. Is there an example of code with some details on how to connect it to the board? I am new to PICaxe and this is my first project. I have had the servo moving on the 28x1 board and have played with led's and a push-button on an 08m so I am getting used to programming but this is the most technical thing I have tried yet so go easy on me! lol

Thanks in advance ;)


Help me connect Xbee to Picaxe!

OK, so I’m going to make a remote control to my next robot. I want to connect a picaxe 28x1 to a Xbee and I have ben trying to find
some good examples but with limited success.

As the Picaxe operates at 5V, whilst the Xbee operates at 3.3V I understand that the signal from the picaxe has to be regulated. (not just the input voltage to drive the device).
Of Cause I could run both the picaxe and the Xbee at 3.3V, but that would just screw with everything else I'm gonna connect to it.

Navigates around via ultrasound on water
Using a
This is my first robot, I started with a boat made out of isolation foam, witch floats really well! The 'Brain' is a Picaxe 28x1 project board and I got the motor + … Read more
Navigates arround controlled by other computer
Using a
Hi, This is my newest project. It is basically formed by two 28x1that are serial controlled by a processing application, one for the motors and other for the two … Read more
I just noticed that a servo and a SRF05 range finder's trigger might be able to share an output pin on Picaxe 28x1 (should work on other models too). It should be … Read more


Hi guys,

I've finally found time to test te ADC and PWM capabillities of my picaxe microcontroller :)

Sorry for my bad english, but I'm a little bit tired ;)



added an SRF05 ultrasound sensor for some cool FX ;)

LCD03 and PICAXE 28 pin Project Board


Does anyone know how to connect a LCD03 to a picaxe 28x project board?

EDIT: I've already connected the LCD successfully to the board :D.

Yet another PWM Picaxe question

I am programming my Mr Basic with Mr Basic moron driver. I use a Picaxe 28x1. It is a very basic setup indeed, with a small servo carrying a sharp IR distance sensor.

After reading many pages of manuals and LMR and example code of other victims, I ran into a wall. It's the dreaded "PWM and servopos don't mix" wall on picaxes.

Navigates around via ultrasound without falling using LED and LDR, Follows lines.
Using a
This is my first homemade robot. It is inspired on the Start Here Robot and Amanda LDR. Changes: Read more

How do I control 18 digital servos with a 28x1?

How do I control 18 digital servos with a Picaxe 28x1?

I have the microcontroller board with the 28x1 mounted and I've tried building the "start here" robo. 

 I now would like to know how to be able to control 18 digital servos since I am building a Hexapod :)

All I really need to know is what extensionboard I need.

Thanks in advance :) Please let me know if you need more info.

RC power for my picaxe

I'm using RC ESC's to drive the motors in my current robot project. These speed controllers has a built in power regulator (called a BEC) that is meant to power your RC receiver. I've measured and the voltage produced is a steady 5.03 Volts.

Can any of you think of a reason why I couldn't or shouldn't use this as power source for my Picaxe 28x1 ? 


Can't seem to insert hyperlinks with Opera browser on my old iMac, so here are a link if you wanna read more about RC ESCs or BECs


PIcaxe 28x1/motor ??? help/problem

you guys might have seen my post over here:



i got help on my first question, but this is my second one:


i have soldered the 2 wires to the board and hooked them up to a motor. i have tried the different  setups (high/low 2/3/4/5/6/7 in the programming editor) number that frits| described in the "start". any1 got any ideas?

i have now got the pic up.



Picaxe 28X1 firmware A.4 has a bug, get a replacement.

As discovered by members of LMR, there is a bug in one version of one kind of Picaxe.

Phil and Limpa described their problems in two different nodes on the site. This thread aims to bring all info together, so we can write a walk through about it.


Phil wrote:


Recognising Buggy Version: 

Tips on EEPROMS, i2c, scratchpad and variables
The picaxe 28X1 has some very cool memory features that can be used to free up program space or to give your robot a more convenient user interface. This post … Read more