MINI-MAX/51-E Support & Frequently Asked Questions

[1] Are all 8051 ports available for my application ?

[2] How can I use MINI-MAX/51-E with Hyperterminal or other terminal programs ?

[3] Which memory model should I select in Micro C for use with MINI-MAX/51-E board ?

[4] Why does download to the board fail ?

[5] I want to read Analog inputs with MINI-MAX/51-E Web Server. What are my choices ?

[6] Is there a 100-Mbit Ethernet version of MINI-MAX/51-E Web Server ?

[7] How can I increase the performance of my MINI-MAX/51-E Web Server ?

[8] How can I add support for devices that are not in BiPOM's list of supported devices ?

[9] Why should I need a MINI-MAX/51-E Web Server when I can do the same with a PC ?

[10] How does the 8051 connect to Ethernet Chip ( CS8900 ) ?

[11] Why is the download slow ?

[1] Are all 8051 ports available for my application ?

P1.5 port pin of 8051 is used by secondary (PIC) processor to change its mode. Hence P1.5 should not be used by user applications except when communicating with the secondary processor to set LCD contrast or PWM output. If P1.5 is cleared  for more than 2 seconds it will restart the whole system.

P1.6 and P1.7 are reserved for I2C Bus Clock and Data (SCL and SDA).

P3.0 and P3.1 are used for hardware serial UART. So your application can use these as long as the use is for serial UART feature ( for example, RS232 receive and transmit ) . P3.0 is driven by the RS232 transceiver chip so you can not set or reset this line in your programs. Also, you can not connect external devices to P3.0. For example, do not connect a servo controller to P3.0; it simply will not work since the RS232 transceiver is holding this line in a low or high state. Connecting external devices that output to P3.0 may damage MINI-MAX/51-E board or the external device.

Ports 4 and 5 are used for Ethernet interface to CS8900A.

All other port pins are available for generic use.


[2] How can I use MINI-MAX/51-E with Hyperterminal or other terminal programs ?

The null modem cross cable that comes with MINI-MAX/51-E crosses RTS and CTS lines from one end of the cable to the other end. Since Hyperterminal and many other programs control the RTS line, these programs keep the boards in Program Mode. Details

[3] Which memory model should I select in Micro C for use with MINI-MAX/51-E board ?

We recommend MEDIUM model which is more suitable for AT89C51ED2 microcontroller. MEDIUM model allows using the Expanded RAM ( XRAM ) for additional variables, large arrays, etc. in user programs.


[4] Why does download to the board fail ?

The MINI-MAX/51-C Downloader has been available for several years now and is a highly reliable downloader. Some customers have even reported that it works better than ATMEL's downloader.

You should only pay attention to few details to make sure that the download works:

1) Make sure that the board is powered.

2) Make sure that you are using the NULL modem cable (that came with the board. Other NULL modem cables may not work. Straight through cables will NOT work.

3) Make sure that you are using the correct serial (COM) port. Some PC's have more than one serial port. Check
Tools->Options->Loader in Micro-IDE for the correct COM port. Baud rate, parity, data bits, stop bits, etc. do not make a difference for MINI-MAX/51-C Loader. All these are automatically detected by the loader. Similarly, the microcontroller type on the board is detected automatically.



4) Make sure that you use the latest software from our website. Older versions of the software may not support newer processors such as the AT89C51ED2. Both the 8051 Development System and BASCOM51 contain the latest MINI-MAX/51-C Loader.


[5] I want to read Analog inputs with MINI-MAX/51-E Web Server. What are my choices ?

Currently, DAQ-2543 board and DAQ-128 board are supported. DAQ-2543 has 11 channels of 12-bit analog inputs. Voltage range is 0 to 4 Volts. DAQ-128 has 8 channels of 12-bit analog inputs. Voltage range is -4 to 4 Volts. Up to 8 DAQ-128 boards and 1 DAQ-2543 board can be cascaded to have a total of 75 (64+11) analog inputs on one web server.


[6] Is there a 100-Mbit Ethernet version of MINI-MAX/51-E Web Server ?

Currently MINI-MAX/51-E Web Server is limited to 10-Mbit Ethernet. Many remote monitoring and control applications do not require 100 Mbit Ethernet because either the data collection is not fast enough to saturate the 10-Mbit connection or the connection bandwidth ( DSL, Cable Modem or Satellite ) is not more than 10-Mbit anyways.

For a 10/100-Mbit Ethernet system, please see our ETRAX LX-100 board that runs Linux.


[7] How can I increase the performance of my MINI-MAX/51-E Web Server ?

Currently, MINI-MAX/51-E Web Server reads HTML and other data files from a Multimedia Card (MMC). This is adequate for most of the applications. Also, the micro-controller on the MINI-MAX/51-E has 2K of RAM which restricts the number of simultaneous connections to 6.

To achieve much higher number of connections and higher speeds, we have developed a memory card called RAM-1 for MINI-MAX/51-E. RAM-1 has 512K RAM and 512K Flash memory. This is an alternative to the Multimedia Card since 512K Flash can store many HTML's and 512K RAM can be used to have several TCP/IP sessions at the same time.


[8] How can I add support for devices that are not in BiPOM's list of supported devices ?

MINI-MAX/51-E Web Server has support for I2C bus commands. Virtually any I2C device can be accessed through the web interface using its unique I2C address.

Also, generic commands and tags are supported to interface with a variety of RS232 Serial devices, LCD's, keypads and the micro-controller digital inputs and outputs.


[9] Why should I need a MINI-MAX/51-E Web Server when I can do the same with a PC ?

For the cost of electricity that a PC uses in less than 1 year, you can purchase the complete MINI-MAX/51-E Web Server. Also, the PC itself costs several times that of MINI-MAX/51-E Web Server when you add the cost of the PC hardware, operating system, web server, analog and digital interface cards and the maintenance.

PC's typically consume several hundred watts of electric power so operating a PC continuously for even few days in a powerless environment with battery power is not possible. MINI-MAX/51-E Web Server consumes under 50mA.


[10] How does the 8051 connect to Ethernet Chip ( CS8900 ) ?

8051 microcontroller on the MINI-MAX/51-E has extra ports P4 and P5. These extra ports are used for connecting the microcontroller to the ethernet chip in a parallel mode.

[11] Why is the download slow ?

If you are using a USB to COM converter such as CBL-USB-COM-1 from BiPOM, please change the latency timer settings of the USB to COM converter. See the document: CBL-USB-COM-1 Speed Improvements