Keypad and LCD Screen to Transmit Data

[pmolsen]

In this posting in 2009 I asked about a simpler method of building a Pixaxe project with keypad/screen (to transmit data to a remote Picaxe):
http://www.picaxeforum.co.uk/showthread.php?11775-Calculator-suitable-to-hack-for-LCD-and-keypad&highlight=pmolsen

Just re-visiting the application again after having no contact with Picaxe stuff since then.

Basically my existing system consists of bulky jiffy box 155mm x 95mm x 50mm with cutouts in the top face for a keypad and AXE033 LCD screen. Inside is a 433MHz transmitter that transmits data to a remote Picaxe. See attached photo. It has a simple menu system to allow me to key in values and select various transmission options.

I want to build another one but am looking for a simpler system than I used before. Have there been any developments since then such as new kits etc. to make it easier? I do see that there are OLED displays now with built-in 08 chip and serial interface that makes that part of it easier. What I am hoping for is a kit from somewhere that has all the bits, maybe excluding the transmitter.

A keypad/screen combo seems like such a standard requirement that I cannot imagine I am the only one wanting something like that.

The other alternative is scrapping the Picaxe for transmitting and using something else entirely, like a smartphone. Anyone know of any apps and/or hardware that will allow 433MHz data transmission?

 

[nick12ab]

The AXE133 has an on board 18M2 which does have some spare pins so if they are enough, you could move your entire project on to this PICAXE and eliminate the need for another.

 

[pmolsen]

Thanks for the suggestion. I would have to pull the old one apart and check but from memory pin shortage was a problem. The keypad and transmitter used up quite a few.

The other problem is that I used up all the program storage on the old 18x. I doubt the on board 18M2 would have room for my program if it also has the code to drive the oled display. Will check the datasheet and see if it says how big the built-in program is. (Question then is can you download that code on its own to reincorporate in your own program?)

 

[srnet]

Question then is can you download that code on its own to reincorporate in your own program?

Well the basic code for the 18M2 code for the AXE133 is available as a download on the PICAXE website, so one presumes they dont mind people downloading it and using it.

The code uses 185 bytes of space in the 18M2 (9%)

 

[westaust55]

4D Systems have some LCD displays with touch screen feature.
Typically van be operated via serial comms or using their own "OS"

 

[Bill.b]

have a look here. this is a keyboard input using one analogue input. I'm shaw it can be addapted to picaxe.

http://www.duinomite.com/duinomite-4x3-keypad-on-1-analog-pin/


Bill

 

[westaust55]

The 1 input keypad was posted on our very own PICAXE forum by BCJKiwi back in 2007 here : http://www.picaxeforum.co.uk/showthread.php?7791-ADC-or-one-input-Keypad-Decoder
Uses a routine with the READADC command to obtain an analog value and then determine the key pressed.

 

[pmolsen]

That looks like a neat solution. Will have a look at it.

Having said that, I have just ordered one of those little Bluetooth modules: http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=130545269839#ht_1561wt_1164

I am looking at changing the current 433.92MHz receiver module to one of those, then I can (hopefully) communicate with the device via a mobile phone app instead.