Mini-HotSpot
Want
a low budget GMSK HotSpot or repeater system? The Mini-HotSpot is
ideal. Add a 9k6 packet capable analog radio and a PC running KB9KHM's
HotSpot software and you have a node you can use with your D-STAR gear.
The Mini-HotSpot is "Satoshi board" firmware V4.xx compatible (not supplied) and measures a mere 2.5 x 2.75 inches and unlike the "Satoshi" boards has the correct type of USB connector, separate PSU facilities and all the subsequent circuit modifications such as the infamous "1 Meg resistor" and "104 blocking cap".
The Mini-HotSpot has been tested with the Yaesu FT-8900 & FT-857, Motorola Desktrac repeater, Motorola M1225 & Motorola SM50. Most any radio that can support 9600bd packet operation can be used.
As is usual with any project there are some evolutionary issues along the way. These issues are listed in board revision order. Your board revision is printed on the top and bottom of the board.
R2 is connected to the wrong side of C4. Cut the track between R2 and C4. Make a green wire link from R2 to pin 7 of U3.
Pin 17 of U2 is shorted to pin 22 of U2 and pin 22 of U1. Either lift U2 pin 17 or cut the tracks on both sides of U2 pin 17 and make a green wire link from U1 pin 22 to U2 pin 22.
R11 is labeled as 47K on the parts diagram.
Clever buggers will have spotted that there are extra parts on the board that are not in the original Satoshi diagram. These extra parts allow for a separate power supply to be used as well as the addition of a DC blocking capacitor in the RX audio feed. These extra parts are;
C99 = 0.1uF (104) capacitor
D40 = 1N4001 diode
U40 = 78L05 voltage regulator
R40 = 4K7 resistor
LED40 = LED
If you choose to power your board from a 12v power supply rather than from the USB power source then DO NOT make the link "LNK" next to C15. Don't try to be cute and install a diode in place of LNK either. The voltage drop across the diode will render your Mini-HotSpot useless.
The pinout for the DB9M is as follows;
V1.02 (silver coloured board)
1 = COS/COR/SQL
2 = RX audio from radio (from Data out)
4 = PTT
5 = GND
6 = TX audio to radio (to Data in)
9 = +12VDC
V1.05 (green coloured board. Also says V1.02 on the reverse)
1 = TX audio to radio (to Data in)
2 = COS/COR/SQL
3 = RX audio from radio (from Data out)
4 = PTT
5 = GND
9 = +12VDC
The jumper settings for both V1.02 and V1.05 are as follows;
SW1 = negative going COS/COR with +5V pullup
SW2 = positive going COS/COR
SW3 leftmost = negative COS/COR
SW3 rightmost = positive COS/COR
SW5 = leave open
The placement diagram is here.
Clever buggers will have spotted that there are extra parts on the board that are not in the original Satoshi diagram. These extra parts allow for a separate power supply to be used as well as the addition of a DC blocking capacitor in the RX audio feed. These extra parts are;
C99 = 0.1uF (104) capacitor
D40 = 1N4001 diode
U40 = 78L05 voltage regulator
R40 = 4K7 resistor
LED40 = LED
If you choose to power your board from a 12v power supply rather than from the USB power source then DO NOT make the link "LNK" next to C15. Don't try to be cute and install a diode in place of LNK either. The voltage drop across the diode will render your Mini-HotSpot useless.
The pinout for the DB9M is the same as for the V1.05 board.
Parts placement/schematic diagram is here.
Copyright 2009-2010 ENIcommunications Corp. All rights reserved.
The Mini-HotSpot is "Satoshi board" firmware V4.xx compatible (not supplied) and measures a mere 2.5 x 2.75 inches and unlike the "Satoshi" boards has the correct type of USB connector, separate PSU facilities and all the subsequent circuit modifications such as the infamous "1 Meg resistor" and "104 blocking cap".
The Mini-HotSpot has been tested with the Yaesu FT-8900 & FT-857, Motorola Desktrac repeater, Motorola M1225 & Motorola SM50. Most any radio that can support 9600bd packet operation can be used.
As is usual with any project there are some evolutionary issues along the way. These issues are listed in board revision order. Your board revision is printed on the top and bottom of the board.
Rev V1.02 - V1.05 (homebrew testers and initial production batch of 50)
The diagram in the files package downloaded elsewhere refers to U4. U4 was renamed U2 on my board.R2 is connected to the wrong side of C4. Cut the track between R2 and C4. Make a green wire link from R2 to pin 7 of U3.
Pin 17 of U2 is shorted to pin 22 of U2 and pin 22 of U1. Either lift U2 pin 17 or cut the tracks on both sides of U2 pin 17 and make a green wire link from U1 pin 22 to U2 pin 22.
R11 is labeled as 47K on the parts diagram.
Clever buggers will have spotted that there are extra parts on the board that are not in the original Satoshi diagram. These extra parts allow for a separate power supply to be used as well as the addition of a DC blocking capacitor in the RX audio feed. These extra parts are;
C99 = 0.1uF (104) capacitor
D40 = 1N4001 diode
U40 = 78L05 voltage regulator
R40 = 4K7 resistor
LED40 = LED
If you choose to power your board from a 12v power supply rather than from the USB power source then DO NOT make the link "LNK" next to C15. Don't try to be cute and install a diode in place of LNK either. The voltage drop across the diode will render your Mini-HotSpot useless.
The pinout for the DB9M is as follows;
V1.02 (silver coloured board)
1 = COS/COR/SQL
2 = RX audio from radio (from Data out)
4 = PTT
5 = GND
6 = TX audio to radio (to Data in)
9 = +12VDC
V1.05 (green coloured board. Also says V1.02 on the reverse)
1 = TX audio to radio (to Data in)
2 = COS/COR/SQL
3 = RX audio from radio (from Data out)
4 = PTT
5 = GND
9 = +12VDC
The jumper settings for both V1.02 and V1.05 are as follows;
SW1 = negative going COS/COR with +5V pullup
SW2 = positive going COS/COR
SW3 leftmost = negative COS/COR
SW3 rightmost = positive COS/COR
SW5 = leave open
The placement diagram is here.
Rev V1.06
There are no known issues with this board.Clever buggers will have spotted that there are extra parts on the board that are not in the original Satoshi diagram. These extra parts allow for a separate power supply to be used as well as the addition of a DC blocking capacitor in the RX audio feed. These extra parts are;
C99 = 0.1uF (104) capacitor
D40 = 1N4001 diode
U40 = 78L05 voltage regulator
R40 = 4K7 resistor
LED40 = LED
If you choose to power your board from a 12v power supply rather than from the USB power source then DO NOT make the link "LNK" next to C15. Don't try to be cute and install a diode in place of LNK either. The voltage drop across the diode will render your Mini-HotSpot useless.
The pinout for the DB9M is the same as for the V1.05 board.
Parts placement/schematic diagram is here.
Modifications and upgrades
Modificatons and upgrades are not supported. The following information is provided for information only.- DUTCH*Star firmware. Upgrading your board to run the DUTCH*Star HSA firmware will require the addition of a 10K resistor between +5V and PIN1 of the PIC. PIN2 of the PIC will need to be grounded to force the bootloader to enable. Once the firmware is installed the ground should be removed for normal operation. Replace ground again when bootloader mode is desired.
Copyright 2009-2010 ENIcommunications Corp. All rights reserved.