As Cisco instructor for CCNA and DevNet on a Secondary Technical School, sometimes I give live demonstrations on Cisco devices. These devices a mounted in racks, so it should be handy to have a wireless console connection. This Christmas Holiday I developed a Bluetooth Cisco Console connection. It it rechargeable due to earlier development of a LiPo/Lio charger. Here it is:
It it build with the following components with a total cost of about € 26,- :
- Li-Po/Li-Ion Charger (€ 5,15, self build)
- Li-Po 2000mAh (€ 9,50 TinyTronics.nl)
- AK-RS232 – TTL to RS232 Converter – Without plastic case, Male (€ 4,90 Artekit.eu)
- 100k resistor, 470E resistor, 3mm LED.
- HC-05 Bluetooth module with adapter (€ 6,45 OpenCircuit.nl)
- Switch KCD1-11 10x15mm.
- 3D printed housing.
As you can see in the picture, the TxD should have a pull-up resistor of 100k. Otherwise you cannot send data, due to electrical misconfiguring. I have extended the LED on the HC-05 module to the outside of the housing so you can see the status of the connection. The other LED on the Li-Po charger lit up when the battery is fully charged.
You could also use the HC-06 module (only slave mode) in this project. You do not have to do much on programming. On my module the version of the software was 3.0. I only changed the name and the password. Other parameters were left default. The default speed was already 9600 baud.
This HC-05 module uses Bluetooth 2.0. The advantage is that it will connect to PC/Mac very easy. The disadvantage is that it uses more power and less range. The range is about 10 meter as the BT2.0 protocol describes. I tested with a wall between the MacBook and the device and about 5 meter distance.
I tested in the classroom, without students. The distance was about 12 meter in line of sight. You can see it hanging at the console cables.
Electrical connections
