Contact
Home Electronics Software Miscellaneous
µServer
AIR
BluePrint
16x16 Matrix
µTetris MSP430
USB Power Monitor
WeatherDisplay
Winamp Control
CPC
AVR ISP Insulator
Logic Insulator
USB Insulator
USB UART Insulator
AVR: LCD Driver
AVR: USB Stuff
AVR: De-Bricker
Temp-O-Clock
Touch-O-Clock
Digital Analog Clock
Block Clock
Binary Clock
Module: Rambo-S
Module: INA226
current sensor
Module: Nokia LCD
Module: misc
voltage modules
Module: DS3231
RTC
Module: VS1011e
MP3 decoder
Module: OSD
Module: SD-Card
Module: USB<->UART
Auto Video Switch
Enctest
GB Camera
Robot: Gizmo
IR Remote Control
Keyboard Extender
Laser Tagger
UV Timer
Thermometer
Telephone Control
Telephone Spy
Games
Blinking Hearts
EGG Timer



There are a lot of printer solutions on the market nowadays. Also the connectivity is excellent by enabling printers with WIFI. However, most printers are expensive to purchase and maintain. Sometimes one just wants to quickly print a recipe, shopping list or even SMS or contacts from one's phone.
For this purpose I wanted a cheap and simple solution. While browsing the web I happened to find this little printer for just €11,- but it had a printer port that is useless with modern PC's and smart phones. So I made a little hardware hack and internally connected an AVR and a BlueTooth module to the parallel printer port. That plus a little C++ was all it took to enable it to print from any device that has BlueTooth.
picture
The printer can be set up as a standard Generic/Text-only printer in Windows utilizing the BlueTooth serial port. Smartphone apps can simply print out strings over the emulated serial port from the Android's BlueTooth device. It prints out neat little thermo paper strips similar to receipts in a supermarket.
picture
I simply sealed the SUB-D 25 printer socket gap with a little piece of plastic.
picture
The circuit was so simple that I just wired it up on a small perfboard. The tiny SPBT2632C2A BlueTooth module was a free sample from ST.
picture
Here the complete gut of the printer can be seen. I managed to identify the CPU as a 87C52 and the actual printer part as MTP201-24B-E. So theoretically it would be possible to make ones own controller board for the printer (maybe a future project).
picture
There is the pinout inside. I de-soldered the SUB-D and then connected the perfboard directly to the printer mainboard.
picture
It is advisable to first de-solder the two screw-plates on either side and then carefully push the black plastic off. This exposes all the pins and makes it possible to simply de-solder all the pins separately.
LAST
NEXT