标签: tracker

NB Tracker软硬件设计开源资料分析（GNSS定位+基站定位） 一 、系统综述 1.项目综述 NB Tracker开源定位器项目，支持NB通讯，支持GNSS获取当前位置信息，同时也支持基站获取当前位置信息，上报到阿里云等平台。 2.产品系统框图 系统框图 功能简介 1. 电源：向SOM核心板，以及扩展外设提供电源 2. SOM核心板：产品核心部分 3. NB天线：信号接收发送 4. GPS天线：接收GPS信号 二 、组件产品资料 1 开发板 产品功能描述 SOM板，是开源产品（DTU和RTU等）的公共核心板。 产品资源介绍 SOM板一共引出了两排插针，用户可用的接口有4个GPIO，可以作为普通输入输出GPIO，也可以作为串口；2个ADC；一组4线SPI；一组I2C；两个串口固定作为AT串口和调试串口。 电源电路 AM21EV5/V6模块 GPS I-PEX座 NB I-PEX座 SIM电路 排座 电源 GPIO UART I2C SPI ADC 产品形态 NB Tracker只有一种产品形态，可以直接作为开发板。 三 、场景应用系统级产品版本定义 3.1 牛羊定位（基站定位） 产品功能描述 设备周期性唤醒，基站定位，上报给云平台。 产品软件模块 AT指令模块 定位模块 通信模块模块 产品软件通讯协议 上行信息： JSON { "deviceID": "216548", "IMEI": "864548040553201", "ICCID": "898607B32619C0388032", "CSQ": 31, "battery": 3600, "longtitude": "116.16461", "latitude": "38.134845", "uploadFrequency": "test", "timeout": 30, "reconnection": 0, "reconnectionNumber": 3 } 下行设置： JSON { "uploadFrequency": 3600, "timeout": 20, "reconnection": 3, "reconnectionNumber": 3, "imei": "864548040553201" } 产品基站定位DTP平台 购买开发板，包含500次的基站定位次数。通过HTTP接口，携带IMEI号信息，调用来获取当前位置。 产品数据平台（阿里云） 接收NB Tracker数据，显示数据，下发配置信息给设备。 3.2 牛羊定位（GPS定位 + 基站定位） 产品功能描述 设备周期性唤醒，GPS定位，上报给云平台。 产品软件模块 AT指令模块 定位模块 通信模块模块 产品软件通讯协议 上行信息： JSON { "id": "123", "version": "1.0", "params": { "GeoLocation": { "value": { "Longitude": 39.9935723, "Latitude": 39.9935723, "Altitude": 0, "CoordinateSystem": 2 } } }, "method": "thing.event.property.post" } 产品基站定位DTP平台 购买开发板，包含500次的基站定位次数。通过HTTP接口，携带IMEI号信息，调用来获取当前位置。 产品数据平台（阿里云） 接收NB Tracker数据，显示数据，下发配置信息给设备。 四、电源方案 采用USB线直流电源或者锂电池 五、天线方案 NB天线：小辣椒天线，通过I-PEX座和底板连接。 标准尺寸。 GPS天线：陶瓷天线，通过I-PEX座和底板连接。 标准尺寸。 六、产品结构 产品结构示意图： 七、产品定义 点击图片可查看完整电子表格 八 、NB Tracer开源产品硬件资料包 详情请 点击此处 九 、NB Tracer开源产品软件代码讲解以及使用 详情请 点击此处 十 、NB Tracer开源产品固件 详情请 点击此处 十一、如何了解更多NB Tracer开源产品方案 请到 奇迹物联的Wiki知识库 了解更多的内容！ 本文章源自奇迹物联开源的物联网应用知识库Cellular IoT Wiki，更多技术干货欢迎关注收藏Wiki： Cellular IoT Wiki 知识库 （https://rckrv97mzx.feishu.cn/wiki/wikcnBvAC9WOkEYG5CLqGwm6PHf） 欢迎同学们走进AmazIOT知识库的世界！ 这里是为物联网人构建的技术应用百科，以便帮助你更快更简单的开发物联网产品。 Cellular IoT Wiki初心： 在我们长期投身于蜂窝物联网 ODM/OEM 解决方案的实践过程中，一直被物联网技术碎片化与产业资源碎片化的问题所困扰。从产品定义、芯片选型，到软硬件研发和测试，物联网技术的碎片化以及产业资源的碎片化，始终对团队的产品开发交付质量和效率形成制约。为了减少因物联网碎片化而带来的重复开发工作，我们着手对物联网开发中高频应用的技术知识进行沉淀管理，并基于 Bloom OS 搭建了不同平台的 RTOS 应用生态。后来我们发现，很多物联网产品开发团队都面临着相似的困扰，于是，我们决定向全体物联网行业开发者开放奇迹物联内部沉淀的应用技术知识库 Wiki，期望能为更多物联网产品开发者减轻一些重复造轮子的负担。 Cellular IoT Wiki沉淀的技术内容方向如下： 奇迹物联的业务服务范围：基于自研的NB-IoT、Cat1、Cat4等物联网模组，为客户物联网ODM/OEM解决方案服务。我们的研发技术中心在石家庄，PCBA生产基地分布在深圳、石家庄、北京三个工厂，满足不同区域&不同量产规模&不同产品开发阶段的生产制造任务。跟传统PCBA工厂最大的区别是我们只服务物联网行业客户。 连接我们 ，和10000+物联网开发者一起 降低技术和成本门槛 让蜂窝物联网应用更简单~~ 哈哈你终于滑到 最重要 的模块了， 千万不！要！划！走！忍住冲动！~ 欢迎加入飞书“开源技术交流群”，随时找到我们哦~ 点击链接 如何加入奇迹物联技术话题群 可以获取加入技术话题群攻略 Hey 物联网从业者， 你是否有了解过奇迹物联的官方公众号“ eSIM物联工场 ”呢？ 这里是 奇迹物联的物联网应用技术开源wiki 主阵地，欢迎关注公众号，不迷路～ 及时获得 最新物联网应用技术沉淀发布

As I said in my previous blog , my new Fitbit Zip is proving to be an amazing motivator when it comes to exercising. I now find myself going out of my way to walk a few more steps, just to see them reflected on my personal online dashboard. Having said this, there are a few considerations of which users should be aware... First let us remind ourselves that there are three members of the Fitbit Family, as follows: * Fitbit Flex: Wireless Activity + Sleep Wristband * Fitbit One: Wireless Activity + Sleep Tracker * Fitbit Zip: Wireless Activity Tracker Each is worn and used in a different way. I have the Fitbit Zip as shown below. This comes with a clip (not shown in this image) that allows you to attach your Fitbit just about anywhere on your person.   As an aside, I would like to note that the Fitbit's clip is a wonder of modern materials technology and engineering. It really grips your clothing, making it practically impossible for you to lose your Fitbit, even if you are running at high speed. Now, before we proceed to the main thrust of this blog, I must say that I was a little surprised to get the following feedback: You were walking on the treadmill while writing your post and the Fitbit on your wrist. So your arm was not moving/swinging with every step you were taking? And you expect the Fitbit to record your step without your arm swinging? What nonsense is that? The Fitbit and every other similar arm/wrist band pedometer that pretends to count your step while sitting on your arm is making fools of consumers like you. And once the step count is wrong, every other information such an instrument gives out is wrong. Did this never occur to you? Well, someone certainly got out of the wrong site of the bed this morning, didn't they? Having said this, after re-reading the above comment a few times, I'm beginning to wonder if the poster's antagonistic and resentful tone is based on the fact that he or she spent some time walking on a treadmill while wearing an armband activity recorder without swinging his or her arm, and that he or she is still disgruntled by the fact that those steps weren't counted towards that day's total (LOL). I replied to the poster saying: "Did I say the Fitbit was on my wrist? (No) Do I look like an idiot? (Don't answer that :-)" The thing is that "I R an engineer," so the potential for these problems had—of course—occurred to me. This is why I had already investigated the situation as described below. The first thing that struck me when I donned my Fitbit Zip was that you wear this little beauty throughout the day and there's no way to turn it on and off. The reason this was of interest to me is that my ride home involves a bumpy road that seems to breed potholes, so I wondered if driving in my truck would trick my Fitbit into thinking I was walking or running. All I can say is that there is some serious DSP (digital signal processing) taking place. I checked the step count before I set off and again when I arrived home. After travelling more than 10 miles over a very boisterous route in the "bumps department," my Fitbit Zip had only incremented its count by two steps. Personally, I think this is little short of miraculous. The next morning when I came into work, I decided to try a few things. My typical garb in the summer is shorts, sandals, and a Hawaiian shirt. My leather sandals tend to flap around a bit, much like flip flops. Keeping this picture in mind, I noted the current step count and then started to walk around my office building with the Fitbit clipped to my shirt's breast pocket. I counted 100 steps and then stopped and checked the count against my Fitbit. Sad to relate, there was a noticeable error. I then repeated the experiment with the Fitbit attached to different parts of my body (well, to different parts of my clothing) as illustrated below:   I might note that all this took a lot longer than you might expect. I didn't have a piece of paper or a pen with me, so I was doing it all in my head (which is why I don't recall the exact values). Also, I'm easily distracted, so I'd see something interesting and lose my count, or I'd stop at 100 steps and realise I couldn't recall the starting value. I'm sure the other folks in the building (a) got tired of seeing me walking past their windows and (b) wondered what the heck I was doing. The bottom line is that in each case (Fitbit clipped to shirt pocket, short centre, trousers side picket, and trousers centre), there was some amount of error in the step count. I found this to be a little disquieting. I'm a bit of an obsessive compulsive when it comes to things like this. You can call me old-fashioned if you will, but I do like my numbers to add up to the correct value. Of course, most folks don't perform serious training in flip flops, so my next step (no pun intended) was to exchange my sandals for socks and sneakers and to repeat the experiment. In this case, I'm delighted to say that my Fitbit Zip was pretty much 100 per cent accurate irrespective of the location to which it was attached—I don't think it ever miscounted by more than one step per test. Now, this is where things get interesting, because I then repeated the entire suite of tests while walking on the desk treadmill in my office. What do you suppose I saw? I have to admit that I wonder if Truthfinder is reading this column. I still hear (in a metaphorical sense, of course) his or her words ringing in my ears: "Did this never occur to you?" I must admit to feeling a tad miffed by this; perhaps even a mite peeved, if you will pardon my language. (See also England raises threat level from "Miffed" to "Peeved" ) So, just to remind ourselves, the following tests were performed on the desk treadmill in my office. This treadmill is very accurate when it comes to counting one's steps. The great thing is that I can watch it counting as I walk, so I have 100 per cent confidence in the values reported by the treadmill. Once again, as reflected in the image below, I performed the tests with the Fitbit clipped to four locations: my shirt pocket, the middle of my shirt, my trousers side pocket, and the middle of my trousers. The reason for the different amounts of time (number of steps on the treadmill) for each test is that I had to keep on stopping to answer the phone.   I calculated the delta percentage error in the step count using the absolute value of the treadmill count (which we know to be correct) minus the Fitbit's count, all divided by the Fitbit's count and then multiplied by 100. Now, remember that all four Fitbit-attachment locations reported accurate values when I was walking around the car park on a solid (asphalt) surface. In some cases, however, walking on the treadmill causes the Fitbit to "throw a wobbly" as it were. The worst-case scenario occurs when the Fitbit is clipped to one's shirt pocket (a whopping 55.57 per cent error). The best-case scenario is when the Fitbit is clipped to the centre of one's trousers (a miniscule 0.1 per cent error). Personally, I am more than happy with a 2-step (0.1 per cent) error out of 1,936 steps. I can live with that. I should, however, note one last point, which is that all of my tests were performed while walking—it may well be that the picture changes when one is jogging or running. Consider the first test shown above in which the Fitbit was attached to my shirt pocket. While walking on the treadmill, the Fitbit reported far fewer steps than I actually took. It may be that, if one were jogging—which can cause a Fitbit attached to one's shirt pocket to bounce up and down a few times—the Fitbit might end up reporting substantially more steps than one had taken. But since I am not a big fan of jogging (you have to look after your knees), I'll leave that experiment to someone else. If you decide to perform that experiment yourself, please share the results with the rest of us. Well, I think that will do for now. Please comment below if you have any questions or thoughts (preferably on the topic of wearable electronics, but I'm happy to talk about almost any topic—the real trick is to get me to stop talking). Until next time, have a good one!