Dave_Wheeler

Hi Atom, OK, this is good. If the LED flickers connected to where pins 2 and 3 go then the Midi input makes it to the opto and there is sufficient drive. When you made the test circuit, what value pull up did you use ?? did you check the value with a meter ?? Now comes the silly question....have you got a good clean 5V supply and are you sure the opto is the right way up ? seems like a silly question but with some devices, pin 1 is not obvious Dave

Hi Atom, The first test is an easy one. To check the stuff before the opto unplug it and connect and LED between pins 2 and 3 (cathode at 3) it should 'flicker' when midi in is present. If this passes, then the problem is either the 6n138 or beyond. if it fails it is before. Good Luck Dave

Thanks TK, Happy New Year.... Couldn't find your 16mS timer but in my code I have a 1mS ISR timer so I can use a similar method. Funny how quick you forget things, the last couple of projects have been 16F based to allow other members of our radio club to make updates, looking at 16 bit intructions and your macros took a bit of 'tuning in' Plan is: Read port (bits 0 and 1 where my encoder is) copy to bits 0 and 1 of my encoder state register Check if different to last read, if same return debounce call lookup table (based on last and present, 4 bits 0x00 to 0x0F) check if direction flag(s) is set, if set check returned value is valid, if not. Tidy up and return If valid, copy present reading to last reading (bits 2 and 3 of my encoder state register) start direction timer / flag(s) (cleared in ISR) process up / down / same I did think about using the upper 4 bits for further checking as well Will write the code tonight and see how it goes. Thanks Again. Dave

Hi All, Sorry for being cheeky but this is not a midibox question. I am having an absolute nightmare trying to get reliable up/down code running for a mechanical 2 bit 36 detent grey code encoder. If I allow time for the worst case bounce (about 15mS !!) I miss good samples and subsequently my lookup table which processes based on last good read (bits 2 and 3) and current read (bits 0 and 1) goes off to la la land and then recovers. Does anyone have some sample code that is known to work with noisy encoders ?? Thanks Dave

Hi, You need to consider what that poor little 7805 is being asked to do. If you have 19VAC, after the rectifier you will have close to the peak voltage which is 19/0.707=26.8VDC. The regulator will have to dissipate 21.8V. so for example if you are pulling 100mA your regulator has to dissipate 2.6W, however if the LCD backlight is on you are likely to be pulling more like 700mA which means you have to dissipate around 18W all of which is dissipated as heat. Just about enough to warm a cup of coffee :) :) Dave

Hi Pay_c. I like both :) :). For me it depends very much on the use. Far all of my DIY targets I use PIC, yes they have their quirks but generally they do what it says on the label :) I also only code in asm. Some of this may be me being lazt as I have a good library that I have built up so 'most' things I want to do, I just grab some modules and bolt them together. At work I use all sorts of processors, It depends a lot on what is the best price at design time. I have used the baby 10 series PICs, AVR, AVR Mega, ARM core stuff and some other odd ball processors. I think what I am getting to is that it depends soooooooo much on the application. For example I have just completed an amateur TV 23cms repeater logic based on a single PIC, PIC chosen as easy for someone else to support. The ICD 2 is not a lot of money and makes debugging very easy, MPLAB is free. For some other processors the tools can be very expensive and you may still have limited debugging available. Of course if you write you code without any bugs and it always works first time then this will not matter :) :) Cheers, Dave

Great Site Attila, There is also a more complex unit on the same site. I have built the EPE tuning control and metronome (PIC Based :)) Dave

Well done, the satisfaction of getting something to work is worth the late nights :) Dave

Thanks Guys, Found exactly what I was looking for in an old edition of EPE which also includes instrument tuning and runs on a pp3 battery. No display but worth loosing that for portability after all it is for my 13 year old daughter :) Cheers, Dave

Hi Does anyone have a design for a metronome. It needs to display BPM and have adjustable accent (1/1 - 1/8) Trying to avoid reinventing the wheel. TIA Dave

Hi Duff, Trying to be as unbiased as possible :) :) I have never used either the hardsid or vst so cannot give realistic comments on performance. If you have lots of money and want a plug and play solution one of them 'may' be a good option. The Midibox SID does have some 'real' advantages. As the software is open source you have the opurtunity of creating a SID based instrument to do exactly what you want. The sound quality is down to the SID itself so any instrument that uses 'real' SID's will feature the SID quirks :) I think the Midibox SID gives more flexibility than anything else. So at the end of the day, you pays your money and makes your choice !! Cheers, Dave

Hi Think about what is happening.... btfss CHAOS_DCO1_WAVE, 0 ; if CHAOS_DCO1_WAVE, 0 is set, skip next instruction bcf CHAOS_DCO1_WAVE, 0 ; Not set so clear it, but it is already clear bsf CHAOS_DCO1_WAVE, 0 ; set it again regardless The bit will always be set. Dave

Not exactly related but I am sure will be of interest. Propellerhead have made Rebirth RB338 FREE. Works great with a MidiBox controller. For any that don't know RB338 is a TB303, TR808 and TR909 in software, not quite as 'raw' as the real thing but gives some great sounds. To get it, go to http://www.rebirthmuseum.com/ You will need to register to download (torrent) Dave

In this context, think of logic levels as being +5V and 0V. A logic input that is not pulled up (or down) is in an unknown state so if there is a pull up, the input is pulled to the +V rail, if there is a pull down the input is pulled to 0V. The value of the resistor determines the current when the input is pulled to the other state. For example, a 10K pull up to 5V----connect input to 0V---current is 5/10000 Ampere (not including any current that the input pulls) Dave

Hi George, Don't use MB64 here but looks like you will need to create a new LCD file (base is on "cs_m_display_2x20.inc") couple of changes to main.asm (#Defines and includes) and then make sure the Cursor position is set to suit. Be carefull as some 2*40 lcd's think they are 4*20 with regard to cursor. Dave

Hi George, Mchip changed the project file format completly with V7.x it now has a .mcp extention. The 'killer' is normally associated with the project options, for example my programmer will only work with an INHX8M format .hex file. The default is INHX32. I don't know what format the original file from TK is. This is changed under the build options. My opinion is that you should always specify the radix in your 'main' asm file and do what TK does and specify the radix when used. 0x13 is hex, so is 13H, 'D'19 is the same but in decimal and 'B' 00010011 is a method of using Binary. I am sure the is other ways as well. I have not been following your original problem, could you point me to the thread. Cheers, Dave

What Duggle suggested is exactly what I have done. I have a 13.8V supply available anyway so I feed a 7809 with 100uF smoother and 2*100nF antiparasitic caps, the output feeds the 9V rail and also feeds the input of a 7805 with similar caps, output of 7805 feeds 5V rail. Downside is that the 7809 is carrying full current for both the rails but with suitable heatsink is good for about 1A which is much more than needed. Dave

Hi Adam, Yep, same seller. Yours might be OK, maybe I was just unlucky :-( Also the item is listed as 6581R3. I got 1 R3, 1 R4 and 1 Rnothing If you are anywhere near Hampshire, will gladly test yours for you. Dave

If you bought yours from the same guy as me be carefull. Pre-sale, nice as pie and very helpfull. Post sale, once I found that one of the three I bought was faulty, took 3 days to get a reply to my email telling me that sending him 3 emails was not the way to contact him and that he needed the item number etc. sent that earlier in the week and no reply at all. If anyone else is going to buy I suggest getting written confirmation that a faulty SID will be replaced before parting with any cash. I looked back through the feedback and it looks like there have been other dissapointed customers as well. You have been warned Dave

Hey Paul, I had a similar problem a while ago and in my case it was found to be that the sysex settings in MidiOx were wrong. As the chip only has the bootloader you may need to reprogram and tweak the settings, if you are using Serge's tool then I don't know as I don't use it. Dave

Hi, I have a small but annoying problem :-) When I change patches on the SID I sometimes get a pop on the audio out. Has anyone else heard this ? Any ideas what the cause is ? Thanks Dave

Hi Daveojo, OK, Simple instructions. Unplug SID chip from C64. Get big hammer and smash the rest as it is not used :) :) All Joking aside, The MBSID is not an interface to a C64, it uses the SID and can also use the PSU. If you look on the SID page you will see what boards are needed, I built mine on Veroboard as I didn't want to wait for PCB's but you will need 1*core and 1*SID PCB. If you get them from Smash he can also do a pre-programmed PIC at a good price. The PIC 18F452 is the 'Brain' and MIOS is the equivelent to an operating system. With just these 2 boards (populated) and LCD display and some time you can get some noise out of the SID by using the free midi utility called MidiOx and there is also a java based patch editor on the site. If you have problems getting a programmed PIC with the bootloader just ask on the forum as there are midiboxers all over the world (I'm in the UK and will gladly blow a PIC for you). Moving on, for the 'A' control surface you will need a DIN PCB (or some Veroboard) a few switches and a rotary encoder, step B uses more of the DIN board and step C uses DIN and DOUT boards. Welcome to the community. Dave

Well done Jef, Now we are all waiting for some serious retro tunes ....LOL :-) Now is probably a good time to ask about the filter caps you are using for your SID's, have you just taken the 470pF value as read or have you checked values. Even poly caps are generally 5% tolerance which gives a possible 10% between caps, the filters will sound quite different if the values are too far apart. You can always 'tweak' things once you are fully up and running. Well done again, Dave

Hi Jef, OK, links missing = not good :-) The 10K resistors should be connected to 5V at one end and both the input pin and the 74HC165 at the other. The way this works is the inputs are normally held at 5V through the 10K, when the input is activated the input to the 74hc165 goes low (the other end of the switch is connected to 0V) When the switch is pressed the 10K will have 5V accross it and good old ohms law tells us that 0.0005A will flow through the resistor With logic circuits floating inputs are bad news (some micros like PIC's have soft pulls on some ports so external pulls are not needed) I think that with the rest of the links fitted you will see very different results. L8R Dave

Sorry Jef, Your English is much better than my Dutch :-) OK, are you using PCB's from Mike or Smash or home made ?? I would check all the links are fitted first, don't forget the links on the track side of the board. Then with the chips removed, could you check that all the inputs are at 5V (they are pulled up by the 10K's) Dave