• "SPL-153FM" is a high speed, 153 kBit/s (actual channel speed is 153 600 bps) wireless radio (packet radio) LAN controller/modem capable to work up to 1 MBit/s. . Controller is based on a XILINX FPGA "XCS10" chip and on EPPFLEX design [7]. Modem uses FlexNet kernel and is capable to work under Windows 95/98/ME/2000/XP and LINUX.

• "SPL-153FM" has build in radio transceiver for 433MHz ISM band. Receiver has very good sensivity (at least -107.4 dBm[1]). Receiver is a Super-Het FM receiver with 10.7MHz IF frequency. Modulation is true "wideband FM" (not PM, PLL / Phase modulation). Working frequency is 433.8MHz. Transmitter is a high-quality FM SAW crystal based transmitter. This eliminate conflicts with phase distorsions.

• Design is based on two PCB boards: "digital" and "analogue". Digital board is capable to work up to 1 Mbit/s and has two interfaces: one for future DSSS or CCK based transceiver [2] [12] (this connector is compatible with DF9IC modem) and one for traditional analogue narrow-band or wide-band FM transceiver. You can see why DSSS is better than wideband FM by click on link down:

Read about DSSS conceptions by click here!.
If you interest in project please email me or donate this project.

You can read about another interesting project for radio-communication named CCK - here!

• Transceiver has build in loopback for minimizing distorsions when transmitting. Receiver works always and compares demodulated FM signal with transmitted signal. Difference between is decremented by the output signal to give better FM (and linear phase) modulation.

You can find drivers and more information for license here: http://www.afthd.tu-darmstadt.de/~flexnet/

• Output power is near +17dBm to +20dBm at 50ohm [1] . If use good antenna you can reach some good distances between. For example arround 25-45km and more. You can connect high-power amplifier (for example 5W or more powerfull) to optimize link performance.

• Interface for connecting to host computer (PC) is LPT, working on EPP/ECP mode. Radio cotroller has five control LEDs (indicators): for "power status" (ON/OFF), for "receive status", for "transmit status", and two optional status LEDs. Commonly they indicate "data exist" (STA) in internal RAM buffer and "connection status" (CON) but their function depends on software driver. Also modem has build in watchdog transmit timer. The timer can be bypassed if needed.

• Internal RAM (FIFO) buffer is 32 kBytes. This enable buffering of large data packets for speed optimization.

• Radio controller is powered by +12V stabilized adapter externally from the device. This enable to use back-up 12V battery for power independent (AVR) work.

• We offer as a optional part suitable external low cost ground plane omnidirectional antenna [8] for 433MHz ISM band. You can see antenna here!

• This modem is able to work without "direct view" between transmitter and reveiver. For a comparison, modems working on 2.4GHz require "direct view"! Also they require expensive antennas.

At this moment I have build two prototypes, and I make some optimization and experiments. I'll publish detailed information soon.
If you are interest in, please email me. Modem will be ready soon for ordering, as a complete device and as a KIT. I'll publish detailed information about distance tests and performance. I intend to make extension board wich will enable to use ~110/220V POWER INSTALLATION for transmiting and recieving data.

Ordering information

The quantity is very low! You can recieve availability information at: [email protected]. So first send us email with details about how many devices you want, what will be your order (Full version, OEM version or KIT version) and period for your order.

You can see more ordering and price information here!

Drivers & Kernel

"SPL-153FM" uses the same drivers and kernel as EPPFLEX. "SPL-153FM" is 100% compatible with EPPFLEX. The main difference between EPPFLEX and SPL-153FM is that SPL-153FM has integrated high-quality wideband FM transciever (integrated radio-part) for ISM band /433.8MHz/. EPPFLEX has connector for external radio transmitter and reciever. Also EPPFLEX is primary based for 76.8 kBit/s.

What is the EPPFLEX modem?

With the first EPP adapter, published in 1997, BayCom made a big leap toward high speed packet links and network access. The EPP adapter allowed the connection of a normal DF9IC FSK modem to the enhanced parallel port of the PC, achieving bitrates of up to 600kbit/s. With the EPPFLEX modem, which was mainly developed by Thomas Sailer, HB9JNX, BayCom presents a totally new generation of high speed modems based on the experience with the EPP adapter.
Basically, the EPPFLEX modem [7] has the same functionality like the EPP adapter with an FSK modem connected. It integrates all digital functions of the EPP adapter and the FSK modem in a single FPGA (a XILINX XCS-10), thus greatly reducing cost of components. The EPPFLEX modem also contains the analog part of an FSK modem and thus is all one needs (besides of course a special radio) to go on air with FSK modulation up to several hundert kbit/s.
Since the FPGA does not have a memory to store its configuration, it is programmed by the driver when packet operation starts. This has a big advantage: The FPGA can also be programmed to do something completely different, by just loading an other driver configuration! In our case, we use the EPPFLEX also to be used on the PCs ECP port, which allows even higher baudrates. And there also exists a driver, which allows a perfect emulation of 1200Bd AFSK, so you can use the EPPFLEX modem also for conventional packet operation.
The EPPFLEX modem allows a great variety of bit rates, for FSK e.g. from 4800Bd up to about 1Mbit/s (depends on how much data your computer can still handle!). However, one must decide for a bit rate when building or ordering the EPPFLEX, since the analog components of the modems have to be adjusted to this bit rate. But by just changing a few capacitors, an adaptation to another bit rate can be done late. By default, BayCom deliver a bit rate of 76.800bit/s, since this has become most popular in Germany. Other bit rates are available on request.

EPPFLEX Installation

To install, copy the DLL (bayeppflex.dll) into the FlexNet directory. Additionally, you need to install the kernel driver appropriate for your operating system.