BIEQ1/Q2 General Description The BIFQI/2 decoders provides a simple method of interfacing to the BxxCDM family of 8 by 8 dot matrix displays.The Q1 allows numeric digits (hex and code B) whilst the Q2 provides alphanumeric and some punctuation. Each decoder can support 4 CDM displays. They provide the necessary formatting of the data and the SPI interface to the driver chip. The decoder supports digital dimming, decimal points and an undecoded mode. The on board regulator allows powering from a +9v supply or can be bypassed if +5v is available. By connecting the RS232 interface to a PC serial port the displays can be driven by a simple software programme or the keyboard via a terminal emulation programme. A fixed 2400 baud 8 bit ,1 start, 1 stop signalling is employed. All bit mapping is carried out by the decoder thus greatly simplifying the software requirement and development time. Applications include message displays, clocks and counters. tie pe ope e 254mm 254mm O QO 54.0 O ol qe om ' 61 Omm 53.0mm t Header Pinouts: RS232 1 2 3 TX See POV 0 ee RX LED connector 1 2 3 4 Data = 0 Ege | CLK POW e Power selector jumper ] 2 3 th Ve Com oe ee Poy Nexus Machines itd reserves the right to alter or withdraw the product specification and characteristics without prior notice at any time in line with product development. Nexus Machines ltd sole and exclusive warranty is that stated in the warranty article of the conditions of sale. Although every effort is made to ensure this data is accurate no liability is accepted for errors or omissions that may affect the end product. Command protocol The RS232 interface features a simple non-handshake mode of operation. The BIFQ will output a prompt character > when it is ready to receive the start of a command - all commands are two bytes inlength (except for the undecoded mode) and should be sent in the order command byte, data byte. The LEDs indicate if the device is waiting for commands or a command entry is in progress. If the green LED is on then it is waiting for the start of a command. The red Led remains on until all the command bytes are recevied.Once the last byte is received by the BIFQ it will decode the command and action the request. Data sent to the unit during the time that the unit is actioning the previous request will be ignored and lost. The unit issues the command prompt once the action is complete. During the command sequence the returned prompt changes to indicate which command byte the unit expects to receive next. All data sent to the unit is sent as ASCII and this includes data. For example the first byte is usually the number 0 to 3 indicating which display is going to be written to. This is sent as 30H to 33H, 1.e. 0 to 3 in ascii. For data and commands all characters must be in upper case. During data input (for example in undecoded mode the actual bit map to send is in ascii hex, 1.e. 10011001b would be sent as 99 which is 39H, 39H in ascii. The action/Data commands are as follows: Command Byte Data Byte Action DECODED MODE 0 3 (30H to 33H) 0 F or HELP - BIFQ1 outputs character bitmap to addressed digit 0 3 (30H to 33H) Any alphanumeric character BIFQ2 outputs character Bitmap to addressed digit INTENSITY MODE I 0 F (Intensity) Selects output intensity. This can be varied between 0 (off) to Fh (15) fully on. (BIFQ1/Q2) DECIMAL POINT ON S 0 3 (Digit address) A dot in the bottom nght hand comer of a character illuminates to give a decimal point. Used mainly with digits DECIMAL POINT OFF R 0 3 (Digit address) A dot in the bottom nght hand comer of the character is tured off. UNDECODED MODE WwW 0 3 (digit address) Undecoded mode. The first 0 7 (column address) value is the digit address. The 0 F ( MSB of ascii hex data) | second is the column within 0 F (LSB of ascii hex data) the digit and the third and forth the data in ascii hex In undecoded mode the data represents the dots in a column. There are 8 columns within a single display and these are addressed as 0 7 in the W command. Below is a map of the columns and the bit number verses the dot that the bit references. In this device a 1 in the bit sets the dot on and a 0 turns it off. OOO OCOOCOC DO OO OOOO OO OO OOOO OO OOO COCO O & OOO OOOC0CO OOO OCOO0CO OOQDOO0O0C OC OOO OCOO0C 0 Column designation and data bit verses row number for undecoded mode (BxxCDM module) f t f Character 0 Character 1 Character 2 Character 3 | re ea)s- q r | Power +5 Lay Typical connection Serial Cornms From Host fo Typical connection for 4 character display Nexus Machines Itd reserves the right to alter or withdraw the product specification and characteristics without prior notice at any time in line with product development. Nexus Machines Itd sole and exclusive warranty is that stated in the warranty article of the conditions of sale. Although every effort is made to ensure this data is accurate no liability is accepted for errors or omissions that may affect the end product. Technical Specification Supply voltage Supply current Number of SPI ports SPI clock rate RS232 signal levels RS232 baud rate Start bits Stop bits Parity Data bits TTL level inputs Dimming levels Total addressable chrs Operating temperature Note 1: The dot matrix display driver requires a single + 5 volt supply. The regulator on the BIFQ is only designed to power the decoder unit NOT the display. A separate +5 volt supply is required for the LED display. 5 or 9-12 volts (user jumper) 35mA 4 40Khz +-2.0 to +-12 V 2400 baud 1 1 none 8 0.8 max 3.6 min 16 4 -10 C to +70 C Manufacturers Part number BIFQI BIFQ2 Note | Nexus Machines Itd reserves the right to alter or withdraw the product specification and characteristics without prior notice at any time in fine with product development. Nexus Machines Itd sole and exclusive warranty is that stated in the warranty article of the conditions of sale. Although every effort is made to ensure this data is accurate no liability is accepted for errors or omissions that may affect the end product.