I bought this K8048 recently and made the assembly. Once running with a DC 16V supply, and linked to my Dell laptop, the programming application refused to recognize the device.
After having carefully checked all the critical points on the board, I drastically shorten the RS232 cable to virtually nothing : I welded together one male and one female plug pin to pin.
Nothing has changed, and I changed my mind. Maybe my laptop serial port does not send strong signals enought for the kit.
I tried on my wife’s desktop, and it’s working perfectly well with a standard serial cable.
My idea is : a MAX232 IC to reinforce the signal may help this kit working on my laptop. what is your opinion ?
{from another forum user, not on behalf of Velleman.}
Big_Jack
My guess would be that it is not the ‘strength’ of the signals from your laptop, but that perhaps the connector for the serial port is not connecting all the pins that are required. The programmer uses some of the ‘status’ lines of the serial port (you can see which ones by looking at the circuit diagram) as well as the data lines - if these are not connected the programming software cannot confirm the presence of the programmer board. (I think that is why usb-to-serial convertor cables are not supported with this device.)
You are right when you say that all the pins must be connected; that’s what I did when i welded together two connectors male + female pin to pin without using any cable. I also tested my connection.
The only fact that makes sense in my case is that when I use the same cable with two differents PCs, it works with the desktop and doesn’t with the laptop. Thus it can’t be a connection problem.
I am digging in Dell’s support center documentation and I found some diagnostic application to test my COM1 port on my Latitude D505 wich already seems properly configured (no IRQ conflicts ).
The UART from your serial port must be “16550” compatible. That means it must be support 115kb and hardware handshaking. This is possible the problem in one of your PC’s.
USB cables are not supported because the the “timing jitter” because the handshaking (if any) is emulated.
Serial programmer are cheap, and easy to support trough software but we know, there is a limited compatibility.
To be more specific - I wonder whether some of the connections from the serial port on the back of the laptop to the serial port support circuitry INSIDE the laptop might be missing?
(I have no personal experience of this with laptops, but I have encountered a desktop where the internal ribbon cable did not carry all 9 pins.)
Alternatively, might there be a power-saving bios option that toggles the serial port between a ‘data lines only’ and ‘all lines supported’ mode?
{Later: I have just seen that my reply came just after the one from Velleman - I think we are attempting to say roughly the same thing - the laptop must support the ‘status’ signals at the 9-pin connector.}
Thanks for your help, I have not solved the problem for my laptop COM1 port. For programming, I will use the family desktop. with it, the link to K8048 works perfectly.
My laptop is the one i use for my job, and I have no right to open it. so I will not take the risk to change anything on it.
If my programming experience is succesfull, maybe a more expensive programming tool with USB port could be helpfull. At this stage I discovered a new world.
I did not mean to suggest that you should open the laptop to try to solve this problem: I was only putting forward reasons why it might not be working.
Although you have settled on a way of working, I have a couple of other thoughts that might help people who read this thread later.
1] the spec for the Dell Latitude D505 says it has a 16550-compatible Serial port, so that should be OK. But I notice it also has a built-in modem - are you certain that COM1 is the serial port? I think I have seen a machine where COM1 was the modem, and COM2 was the serial port.
2] might there be any other automatically started application software that has control of the serial port - PDA sync software for example?