THeff

I was thinking that the resistor ladder from the AOUTLC could be added to the unused port A (you would loose the LEDs) of the 16F88 and possibly create an AOUT port on the IIC circuit. This would give you MIDI in/out and AOUT in one low cost module. The only snag that I could see is that I think the A4 pin can only sink and not source. Any thoughts on this, anyone? BTW TK, I have my MIDIbox SEQ running V3.1 with the AOUT module, 4 IIC ports, and 4 gates. It works amazing! The adventure now begins to find all of the capabilities that you have hidden is this state of the art machine! Tim

Just a follow-up to the previous message. I received some back-ordered ALPS rotary encoders from Mouser today and they did ship them with the mounting nuts and washers. They must have gotten the message! Tim

Hi Thorsten, Thanks for the update! This is good news because I purchased a lot of the Panasonic encoders. It's weird that the ALPS and Panasonic encoders behave so differently, because they look almost identical from the outside. BTW anyone who wants to purchase the ALPS panel mount encoders from Mouser beware!, they don't send the mounting nuts and washers. I called to let them know that they were missing and they said sorry, that's the way we sell them. They told me I could purchase the hardware seperately if I wanted to. Needless to say I was not very happy! Regards, Tim

I have used the 555 timer circuit that you showed several times in the past and it does work very well. If this LCD is for the SID, you could probably use the 1 MHz PWM clock coming out of the PIC to drive the capacitor/diode network as well. Especially since you only need to "steal" about 1 mA from the clock. The electrolytic coupling capacitor could probably be reduced in value since the clock is 1 MHz and this would provide less of a load on the clock line. Tim

"The only down side is that the LCD display requires ~-2V on the contrast pin for good contrast" Yes, The CORE module has to be modified slightly. The original design has a 10K pot for the LCD contrast. The connections to the pot are (1) ground, ((2) wiper) LCD contrast pin, and (3) +5V. The +5V connection to the pot has to be removed and you need to supply negative 2 Volts to pin # 3 of the potentiometer. I have a +/- 12 V supply for the AOUT module, so it was just a matter of connecting a 1K resistor to the -12 V and the other end to the pot along with a 2 - 3 V zener diode to ground ((cathode/stripe) to ground, anode to pot pin #3 ). I used a 3 V zener because I had several lying around. You only need about 1 mA of current for the negative LCD voltage. You probably could use 3 or 4 regular 1N914 switching diodes in series in place of the zener. Just place them in the opposite direction of the zener because you will be using the forward drop voltage and this should give you about 2.1 Volts. Once this mod is done you adjust the contrast with the 10K pot just like the original design. BTW, BG Micro has a data sheet for the display on there web sight in the technical documents section. Tim

Hi All, If you are looking for some 2x40 LCDs, you may want to checkout BG Micro for part # LCD1025. http://www.bgmicro.com They sell these brand new LCD displays as part of an assembly mounted in a frame with another PCB. The LCD is mounted with screws and is plugged in, so no soldering is required to remove it. The LCD has LED backlighting. The cool thing is that the other PCB has (3 ea.) 74HC595 ICs, (1 ea.) 74HC165, an LED bargraph display, and other misc. components. The only down side is that the LCD display requires ~-2V on the contrast pin for good contrast. The single price is $5.95 or $4.67 if you buy more than three. I bought 10 a while back and just started using them on the MB SEQ and MB SID and they work great. You will have to unsolder the ICs if you want them but the pin leads have not been trimmed, they are full length. I even unsoldered the 16 pin header connector and re-used it for the LCD. Tim

Just a final follow-up, I replaced the Panasonic rotary encoders with ALPS EC12E2420802 encoders from Mouser and they work perfect, using the DETENTED2 option. I tried all three options with the Panasonic encoders from Digikey and could not get them to work reliably. Everything is working great now, including the AOUT module. Regards, Tim

Hi Thorsten, I did try the DETENTED2 option and the results are about the same. The movement is correct in both directions so I don't think it is a wiring issue. I'm wondering if the Panasonic encoders have a lot of bounce in the contacts, because if you move it real slow sometimes it will go backwards and forwards a step or two. Anyway, my Alps encoders will be here Wednesday so I'm just going to change them out. These are detented encoders so it should be better all around. I'll save the Panasonic encs for future projects (MBSID and MBFM). That will give me more time to figure out a soulution. Thanks, Tim

Thanks TK for the explanation. It operates as I thought Fast or Normal. Problem is that in the normal mode with the Panasonic 24 ppr non-detented encoders it skips over entries even when you turn it very slow. You have to go back and forth to catch the desired selection. A predivider of 4 seems to work very smoothly. I will investigate changing this entry in the files you mentioned. I have also ordered some Alps detented encoders from Mouser in the mean time. Thanks again for all your help! Tim

Hi John, I did some more investigation about the MAX6007B and it is a 0.2 % tolerance part at 2.048 V. The best tol. LM336-2.5 is 1% at 2.50 V with no adjustment. I'm not sure if it can be adjusted down to 2.048 V. With the 2.5 V part installed I get 1.000 V and about 4.010 V out when I run the MIDIbox CV calibration program. I was thinking that the MAX part was 2.48 V and not 2.048 V. The LM336 may not be such a great choice after all. Tim

Hi John, I just built mine this weekend and I used an LM336-2.5 that I had on hand and it seems to work very well. It's a TO-92 package with three leads but you only use two of them, the adjust pin it not connected. Tim

Thanks for the replies... OK, I found the three entries in the mios.h file (slow(0), normal(1), and fast(2)). What value does "slow (4)" from the speed program translate to for a value to be placed in the .h file? Also, I thought there were only two speeds - fast or not fast. How are three speeds selected via the fast button? THeff

I guess I am still confused. I did find the speed param for fast (default 3) but how do I change the slow? I am getting double hits and the best speed seems to be "slow (4)" from the enc speed test program. I assumed that it uses the (3) when fast is enabled and then goes back to normal when disabled. If this is true it's the "normal" that I need to change. THeff

Hello, This is my first post on the forum. I just finished building my MIDIbox SEQ and I used Panasonic encoders. I ran the encoder speed test routine and determined the optimum values. I found where to set the MIOS for non-detented encoders, but I can't seem to find where to put the speed values for fast and slow in the SEQ main.asm, or the MIOS tables. It's probably right in front of me but I can't seem to find it. Any pointers would be helpful. Before I close let me say that TK you have done a magnificent job on the SEQ hardware, SW, and documentation! I built the MIDIbox Plus 16 and MIDI monitor years (picture is in your gallery) and they work flawless as well. Thanks!!! THeff