*** Additinal notes by Raphael Assenat raph@raphnet.net, 05/16/20 -- Hardware Notes The linux driver i2c-philips-par works very well with this interface. However, when I built the interface, I did not follow exactly the schematic in this file. Here is a list of what I did differently: 1) The SCL feedback is not required by the driver, so we can safely ignore connections to gates 10-11 and 8-9. Theses remaining gates can be used to drive leds instead :) Please note however that this violates the I2C standard in respect to the ability of slaves to hold SCL low. 2) The linux driver does not check if there is power on the db25 pin #12, so this connection is not necessary. 3) Instead of connecting pins 10,13 and 25 to ground, I simply connected pin 18 to ground. -- Software Notes The interface works perfectly with the I2C driver from the Linux kernel, without any modifications. The required modules are: - i2c-core (Anything using I2C needs it) - i2c-algo-bit (for interfaces that uses bit banging, such as this parallel interface...) - i2c-philips-par (the philps style parallel port interface) - i2c-dev (User space interface to access the I2C Bus) **** ORIGINAL DOCUMENT FOLLOWS **** I2C Printer Port Adapter Schematic ---------------------------------- The file PORTMSC.DWG is a schematic for the I2C printer port adapter drawn using PC style screen drawing characters. This should display on most PC compatible computers. A second file: PORTMSC.PRT is the same schematic re- editted for printing using only normal text characters for printing. The adapter is plugged into the printer port on a PC. Power (+5VDC) must be applied from an external source, since the adapter cannot get its power directly from the printer port. The SCL, SDA, and GND signals must be connected to I2C peripheral(s) in order for them to communicate with the PC. PC-eXtended-ASCII or XPC : 74LS05 pin 14 (Vcc) þ ÚÄÄÄÄÄ¿ ÚÄÄÂÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÂÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄþ 1 ³ ÚÁ¿ÚÁ¿ÚÁ¿ ÚÁ¿ÚÁ¿ÚÁ¿ ÍØÍ.1uF ³ +5V ³ ³ ³³ ³³ ³3x10K 3x10K³ ³³ ³³ ³ 74LS05 ³ ³ ³ ÚÄÄÄÄÄÄ¿ ÀÂÙÀÂÙÀÂÙ ÀÂÙÀÂÙÀÂÙ pin 7 þÄÅÄÄÄÄÄÄÅÄþ 2 ³ ³ 12 þÄÅÄÄÙ ³ ³ 3³\ 4 ³ ³ ³ (Gnd) Ï GND ³ GND ³ ³ 17 þÄÅÄÄÄÄijÄijÄÄÄÄ´ >oÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄijÄijÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ ³ ³ ³ ³ ³ ³ ³/ 8 /³9 ³ ³ 10 /³11 ÃÄÄÄÄÅÄþ 3 ³ ³ 15 þÄÅÄÄÄÄÄÁÄijÄÄÄÄÄÄÄÄÄÄÄÄÄÄo< ÃÄÄÄÄÄÄÁÄijÄÄÄÄÄÄo< ÃÄÄÄÄÙ ³ SCL ³ ³ ³ ³ 1³\ 2 \³ ³ \³ ³ ³ ³ 9 þÄÅÄÄÄÄÄÄÄijÄÄÄÄ´ >oÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÅÄþ 4 ³ ³ ³ ³ ³/ 6 /³5 ³ ³ SDA ³ ³ 11 þÄÅÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄo< ÃÄÄÄÄÙ ÀÄÄÄÄÄÙ ³ 10 þÄÅÄ¿ \³ 4-pin ³ 13 þÄÅÄÅÄÄþ GND Connector ³ 25 þÄÅÄÙ ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ Part List ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» ÀÄÄÄÄÄÄÙ º 1 - .1 uF capacitor º 6 - 10K 5% resistors º 25-pin male D º 1 - 4-pin connector º 1 - 25-pin male D connector º connector to PC º 1 - 74LS05 open collector hex inverter º printer port ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ ------------------------------------------------------------------------- ASCII version: LS05 pin 14 (Vcc) o ------- | | | +--+--+---------------------+--+--+------------+------+-o 1 | | | | | | | ===.1uF | +5V | -------- [R][R][R] 3x10K 3x10K [R][R][R] LS05 | | | | | | | | | | | pin 7 o-+------+-o 2 | | 12 o-+--+ | | 3|\ 4 | | | (Gnd) | GND | | 17 o-+-----|--|----| >o-------------+--|--|--------------+ | | | | | | |/ 8 /|9 | | 10 /|11 +----+-o 3 | | 15 o-+-----+--|--------------o< |------+--|------o< |----+ | SCL | | | | 1|\ 2 \| | \| | | | 9 o-+--------|----| >o-------------------+--------------+----+-o 4 | | | | |/ 6 /|5 | | SDA | | 11 o-+--------+----------------------------------o< |----+ ------- | 10 o-+-+ \| 4-pin | 13 o-+-+--oGND Connector | 25 o-+-+ ------------------ Part List -------------------------- -------- | 1 - .01 uF capacitor | 6 - 10K 5% resistors | 25-pin male D | 1 - 4-pin connector | 1 - 25-pin male D connector | connector to PC | 1 - 74LS05 open collector hex inverter | printer port ------------------------------------------------------- -------------------------------------------------------------------------- END Obtain software from Phillips BBS: 1-800 451-6644 Or write your own!!! Threat [:->] : *********************************************************************** *********************************************************************** *** *** *** Please note: Purchase of Philips' I2C components conveys a *** *** license under the Philips' I2C patent to use the components *** *** in the I2C-system provided the system conforms to the I2C *** *** specifications defined by Philips. *** *** *** *********************************************************************** ***********************************************************************