OpenWrt Forum Archive

Topic: Before I mess - BT HomeHub 2A - questions about JTAG

The content of this topic has been archived on 7 May 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

So I've installed OpenWRT on HH3A and Netgear DG834GT, LEDE on HH5A.
A piece of cake xD. Now it's time for something harder.

So:

if your BT firmware is older than 8.1.H.J you may be able to avoid JTAG

unluckily it's not my case, so I need JTAG. I've already soldered SERIAL and it works fine.

Everything seems to be well explained on the wiki, but I have some questions as it's my first time with JTAG.

First of all, I would love to use Arduino for this purpose. Found github.com/zoobab/tjtag-arduino, which looks cool and understandable for me (I have some experience with Arduino). But how about TTL levels? Everywhere there is a huge red warning saying "look out for voltage". My Arduino is 5V.

Another consideration - what software to use? github.com/zoobab/tjtag-arduino? Will it be compatible?

If JTAG+Arduino is waste of time, what should I look for? What hardware?

I've found (cheap and) popular hardware in my "local" store.

Fully compatible with original Altera USB-Blaster.
    Supported target voltage : 1.0V-5.5V.
    Support all ALTERA deveice.
    CPLD:MAX 3000A、MAX 7000A、MAX 7000B、MAX 7000S、MAX 9000、MAX 9000A and MAX II.

    FPGA:Stratix、Stratix II、Stratix GX、Cyclone、Cyclone II、Cyclone
III、ACEX 1K、APEX II、APEX 20K、APEX 20KE、APEX 20KC、FLEX 10K、FLEX 10KE、FLEX
10KA、FLEX 6000、FLEX 8000、EPCS1、EPCS4、EPCS16、EPCS64EPC1、EPC4、EPC8、EPC16.
    Support:JTAG, AS, PS Mode.
    Support NiosII embeded core based debug.
    Supports Quartus II SignalTap? II Logic Analyzer (for logic analysis).
    High performance, 6 times faster than ByteBlasterII.
    USB interface with status and Power LED.
    Size:5.5cm x 2.8cm x 1.5cm - 2.17inch x 1.1inch x 0.59inch.

What do You think friends?

Best regards!

(Last edited by e-san on 21 Feb 2018, 21:08)

bump.

So there is noone who knows anything about jtag?

Nice.

Yes you will fry your router, if you connect Arduino directly with the JTAG of your router. You need a step down voltage regulator! Which software is suitable for the Arduino I do not know, inform yourself in a more suitable forum for it (search for JTAG TTL arduino). Another way is to buy a USB JTAG device, just look for FTDI FT2232 (these are recommended but others are also suitable for this purpose, just check if there are drivers for your OS).

(Last edited by QFireball on 23 Feb 2018, 16:36)

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